Efficacy of protease inhibitor monotherapy vs. triple therapy: meta-analysis of data from 2303 patients in 13 randomized trials

A detailed characterization of drug resistance during darunavir/ritonavir monotherapy highlights a high barrier to the emergence of resistance mutations in protease but identifies alternative pathways of resistance

BACKGROUND

Maintenance monotherapy with ritonavir-boosted darunavir has yielded variable outcomes and is not recommended. Trial samples offer valuable opportunities for detailed studies. We analysed samples from a 48 week trial in Cameroon to obtain a detailed characterization of drug resistance.

METHODS

Following failure of NNRTI-based therapy and virological suppression on PI-based therapy, participants were randomized to ritonavir-boosted darunavir (n = 81) or tenofovir disoproxil fumarate/lamivudine +ritonavir-boosted lopinavir (n = 39). At study entry, PBMC-derived HIV-1 DNA underwent bulk Protease and Reverse Transcriptase (RT) sequencing. At virological rebound (confirmed or last available HIV-1 RNA ≥ 60 copies/mL), plasma HIV-1 RNA underwent ultradeep Protease and RT sequencing and bulk Gag-Protease sequencing. The site-directed mutant T375A (p2/p7) was characterized phenotypically using a single-cycle assay.

RESULTS

NRTI and NNRTI resistance-associated mutations (RAMs) were detected in 52/90 (57.8%) and 53/90 (58.9%) HIV-1 DNA samples, respectively. Prevalence in rebound HIV-1 RNA (ritonavir-boosted darunavir, n = 21; ritonavir-boosted lopinavir, n = 2) was 9/23 (39.1%) and 10/23 (43.5%), respectively, with most RAMs detected at frequencies ≥15%. The resistance patterns of paired HIV-1 DNA and RNA sequences were partially consistent. No darunavir RAMs were found. Among eight participants experiencing virological rebound on ritonavir-boosted darunavir (n = 12 samples), all had Gag mutations associated with PI exposure, including T375N, T375A (p2/p7), K436R (p7/p1) and substitutions in p17, p24, p2 and p6. T375A conferred 10-fold darunavir resistance and increased replication capacity.

CONCLUSIONS

The study highlights the high resistance barrier of ritonavir-boosted darunavir while identifying alternative pathways of resistance through Gag substitutions. During virological suppression, resistance patterns in HIV-1 DNA reflect treatment history, but due to technical and biological considerations, cautious interpretation is warranted.

Observational study to evaluate discontinuation of monotherapy with cobicistat-boosted darunavir in patients with human immunodeficiency virus

To evaluate the reasons for changing to monotherapy with protease inhibitors, together with the proportion and reasons for the interruption to treatment, in patients who have been treated at some point with cobicistat-boosted darunavir (DRV/c). Outpatients in a tertiary hospital. Observational retrospective study to evaluate monotherapy with DRV/c (800 mg/150 mg) in adult patients with human immunodeficiency virus infection, from December 2014 to July 2022. Demographic variables, viral load, cluster of differentiation 4 lymphocyte lymphocyte count, and antiretroviral therapy were assessed. 42 patients were included. 36% of the patients were undergoing monotherapy at the time of the analysis. The main reason for discontinuation was poor adherence. At time of analysis, 80% of the patients in monotherapy had an undetectable viral load. Antiretroviral therapy recommendations advise against exposing the patient to functional monotherapy with a single drug due to the high risk of virological failure and the onset of resistance to a single drug. Following the analysis of the results, DRV/c in monotherapy is not an effective strategy in the medium and long term due to factors such as lack of adherence or virological failure, although it can be maintained in specific circumstances. Therefore, patients undergoing monotherapy require close monitoring.

Immunological and inflammatory changes after simplifying to dual therapy in virologically suppressed HIV-infected patients through week 96 in a randomized trial

OBJECTIVES

To evaluate whether simplification of antiretroviral treatment to dual therapy (DT) negatively impacts immune recovery (IR), immune activation and inflammation (IA/I), and HIV reservoir.

METHODS

An open-label, single-centre, randomized controlled trial conducted in adult virologically suppressed HIV-infected patients on triple therapy (TT) with elvitegravir-cobicistat, emtricitabine and tenofovir alafenamide or dolutegravir (DTG), abacavir, and lamivudine (3TC). Participants were randomized to continue TT or switch to DTG, or darunavir/cobicistat (DRVc) plus 3TC. IR was assessed by CD4⁺/CD8⁺ ratio at 48 and 96 weeks. Changes in immune activation, proliferation, exhaustion, senescence, and apoptosis in CD4⁺ and CD8⁺ T cells, plasma sCD14, hsCRP, D-dimers, β2-microglobulin, IL-6, TNF-α and IP-10 levels, cell-associated HIV-DNA (CA-DNA), and unspliced HIV-RNA (usRNA) were also analysed.

RESULTS

One hundred and fifty-one participants were enrolled. Fourteen patients did not complete the follow up. In the ITT and PP analysis, the IR was similar between the treatment arms. In the ITT analysis, the median increase in CD4⁺/CD8⁺ ratio was 0.10, 0.04, and 0.07 at week 48, and 0.09, 0.05, and 0.08 at week 96 for TT, DTG/3TC, and DRVc/3TC, respectively. After adjusting for confounding factors, the slopes of changes in CD4⁺/CD8⁺ ratio over time were independent of treatment (F = 1.699; p = 0.436) and related only to baseline values (F = 756.871; p = 0.000). There were no differences in IA/I, CA-DNA, or usRNA between treatment arms.

DISCUSSION

Both IR and IA/I, CA-DNA, and usRNA were similar in the three treatment groups, regardless of maintaining TT or simplifying to DTG/3TC or DRVc/3TC in virologically suppressed HIV-infected patients.

Uptake Success and Cost Savings from Switching to a Two-Drug Antiretroviral Regimen

The emergence of dual therapy for antiretroviral (ARV)-experienced persons living with HIV (PWH) offers the opportunity to reduce lifetime exposure to unnecessary ARV drugs while maintaining viral suppression and reducing the cost of care. Our objective, using retrospective analysis of a quality care initiative, was to examine in routine clinical practice the clinical impact of switching PWH stable on a three-drug to a two-drug single-tablet formulation (STF) ARV regimen. We also examined the cost implications of this STF adjustment. Between January 1, 2020 and January 1, 2021 eligible patients (i.e., virally suppressed, no active hepatitis B infection, no documented nucleoside reverse transcriptase inhibitors/integrase strand transfer inhibitor resistance) were offered, on a convenience basis and as part of routine care, the opportunity to adjust their current three-drug STF to a two-drug STF (dolutegarvair/lamivudine). The acceptance, clinical efficacy, safety, tolerability, and cost of treatment were measured for patients who switched in 2020. Of 989 eligible PWH, 408 were approached and 391 (39.5%) switched to two-drug regimen; 99% remained on the two-drug STF at year's end (median 240 days follow-up). Only 2/391 patients who switched lost viral control. The total ARV drug cost for all 989 patients decreased by 10.3% generating an actual savings of $1,596,666 among patients approached and switched in 2020. Patient interest and uptake in switching to two-drug STF was substantial and resulted in few discontinuations for any reason. It provided significant and immediate cost savings within the first year. Our results bring clarity to discussions on whether using two-drug regimens would be practical and acceptable in nonclinical trial settings.

The proximal proteome of 17 SARS-CoV-2 proteins links to disrupted antiviral signaling and host translation

Viral proteins localize within subcellular compartments to subvert host machinery and promote pathogenesis. To study SARS-CoV-2 biology, we generated an atlas of 2422 human proteins vicinal to 17 SARS-CoV-2 viral proteins using proximity proteomics. This identified viral proteins at specific intracellular locations, such as association of accessary proteins with intracellular membranes, and projected SARS-CoV-2 impacts on innate immune signaling, ER-Golgi transport, and protein translation. It identified viral protein adjacency to specific host proteins whose regulatory variants are linked to COVID-19 severity, including the TRIM4 interferon signaling regulator which was found proximal to the SARS-CoV-2 M protein. Viral NSP1 protein adjacency to the EIF3 complex was associated with inhibited host protein translation whereas ORF6 localization with MAVS was associated with inhibited RIG-I 2CARD-mediated IFNB1 promoter activation. Quantitative proteomics identified candidate host targets for the NSP5 protease, with specific functional cleavage sequences in host proteins CWC22 and FANCD2. This data resource identifies host factors proximal to viral proteins in living human cells and nominates pathogenic mechanisms employed by SARS-CoV-2.

SARS-CoV-2 is the latest pathogenic coronavirus to emerge as a public health threat. We create a database of proximal host proteins to 17 SARS-CoV-2 viral proteins. We validate that NSP1 is proximal to the EIF3 translation initiation complex and is a potent inhibitor of translation. We also identify ORF6 antagonism of RNA-mediate innate immune signaling. We produce a database of potential host targets of the viral protease NSP5, and create a fluorescence-based assay to screen cleavage of peptide sequences. We believe that this data will be useful for identifying roles for many of the uncharacterized SARS-CoV-2 proteins and provide insights into the pathogenicity of new or emerging coronaviruses.

Efficacy and safety of switching to dolutegravir plus lamivudine versus continuing triple antiretroviral therapy in virologically suppressed adults with HIV at 48 weeks (DOLAM): a randomised non-inferiority trial

BACKGROUND

Simplified antiretroviral therapy (ART) regimens are desirable for people with HIV. We investigated the efficacy and safety of switching from triple ART to dual dolutegravir plus lamivudine therapy.

METHODS

DOLAM is a phase 4, randomised, open-label, non-inferiority trial, done at six HIV clinics in Catalonia, Spain. Adults with HIV-1 receiving a triple ART regimen, aged 18 years or older, with virological suppression, a CD4 nadir of at least 200 cells per μL, who were HBsAg-negative, and without previous viral failure or resistance mutations to study drugs were eligible. Participants underwent computer-generated randomisation, stratified by the class of the third drug, and were assigned (1:1) to switch to oral dolutegravir 50 mg and lamivudine 300 mg once daily or to continue triple ART for 48 weeks. The primary endpoint was the proportion of people with an HIV RNA value of at least 50 copies per mL at week 48 (US Food and Drug Administration snapshot algorithm, 8% non-inferiority margin). Both the primary and safety outcomes were evaluated in the intention-to-treat exposed population. The study is completed and was registered with EudraCT 201500027435.

FINDINGS

Between July 7, 2015, and Oct 31, 2018, 265 participants were randomly assigned to switch to dolutegravir plus lamivudine (n=131) or to maintain triple ART (n=134) and all received at least one dose. Nine (7%) participants in the dual therapy group and ten (7%) in the triple therapy group were excluded before 48 weeks, mostly due to treatment discontinuations or virological failure. Participants were predominantly male (116 [87%] of 134 in the triple ART group and 111 [85%] of 131 in the dolutegravir plus lamivudine group). The difference in the proportion of participants with HIV RNA values of at least 50 copies per mL at 48 weeks between the dual therapy group (three [2%] of 131) and triple therapy group (two [1%] of 134) was 0·8 percentage points (95% CI -3·3 to 5·2), showing non-inferiority of dolutegravir plus lamivudine dual therapy compared with triple ART. 73 (56%) of 131 participants allocated to dual therapy had 150 adverse effects, compared with 78 (58%) of 134 participants allocated to triple therapy who also had 150 adverse events (p=0·68). Drug discontinuation due to adverse effects occurred in four people in the triple therapy group and three people in the dual therapy group.

INTERPRETATION

Our findings show the efficacy and safety of dolutegravir plus lamivudine as a simplified therapy switch option for selected people with HIV with virological suppression on triple ART.

FUNDING

Instituto de Salud Carlos III, Red de Investigación en Sida, and ViiV Healthcare.

Factors associated with the use and composition of two-drug regimens in a large single-centre HIV cohort

OBJECTIVES

We aimed to assess the clinical characteristics associated with the use of two-drug regimens (2DRs) and the factors associated with specific antiretrovirals in 2DRs in a large single-centre HIV cohort.

METHODS

Retrospective analysis of demographics, HIV characteristics and AIDS events, antiretroviral prescription, virological failure and genotypic resistance testing, and laboratory results from all adult people with HIV (PWH) prospectively followed at the Hospital Clinic of Barcelona who were receiving a 3DR or a 2DR in January 2020. We assessed factors associated with the probability of receiving 2DRs relative to three-drug regimens (3DRs) using a logistic regression model, controlling for age, sex and year of HIV diagnosis. The same methodology was applied to identify factors associated with the prescription of integrase inhibitor-based regimens or PI-based regimens among PWH receiving 2DRs.

RESULTS

There were 3432 (88%) PWH receiving 3DRs and 463 (12%) receiving 2DRs. In the final adjusted model, ≥2 previous virological failures, previous resistance mutations, previous AIDS diagnosis, longer time on current regimen, higher total cholesterol or triglycerides and lower baseline haemoglobin were independent factors associated with 2DRs. The majority of 2DRs included an integrase inhibitor or/and a PI. We identified independent factors associated with the inclusion of integrase inhibitors (lower HDL cholesterol) or PIs (prior AIDS, prior genotypic resistance mutations and lower CD4/CD8 ratio) in the 2DR.

CONCLUSIONS

In this large single-centre HIV cohort, a worse cardiometabolic status or more archived resistance were key factors associated with inclusion of integrase inhibitors or PIs, respectively, in 2DRs.

Five-year follow-up of patients enrolled in the NEAT 001/ANRS 143 randomized clinical trial: NEAT 001/ANRS 143 LONG TERM study

BACKGROUND

Few long-term data are available in subjects having initiated ART with an NRTI-sparing regimen.

OBJECTIVES

Outcomes of subjects enrolled in the NEAT 001/ANRS 143 randomized clinical trial (comparing ritonavir-boosted darunavir + raltegravir versus ritonavir-boosted darunavir + tenofovir disoproxil fumarate/emtricitabine) were retrospectively collected, through anonymized electronic case report forms, up to 6 years post-enrolment.

METHODS

The last NEAT 001 visit (Week 96) was conducted in 745/805 randomized subjects (363/401 ritonavir-boosted darunavir + raltegravir and 382/404 ritonavir-boosted darunavir + tenofovir disoproxil fumarate/emtricitabine). Of these, 430 were enrolled in NEAT 001/ANRS 143 LONG TERM (NLT) study (201 raltegravir, 229 tenofovir disoproxil fumarate/emtricitabine), with a median follow-up of 44.4 months.

RESULTS

During NLT follow-up, the proportion of AIDS, non-AIDS events, virological rebound and serious adverse events, discontinuation for virological failure and for adverse events did not differ between groups; discontinuations for virological failure since NEAT 001 inclusion were more frequent in subjects with baseline CD4 <200 cells/mm3 (11.9% versus 5.3%; P = 0.077). At last follow-up, a quarter of subjects (22.2% for ritonavir-boosted darunavir + raltegravir and 29.7% for ritonavir-boosted darunavir + tenofovir disoproxil fumarate/emtricitabine) were still receiving their initial regimen. Integrase inhibitor exposure was not associated with weight gain (P = 0.48), while tenofovir disoproxil fumarate exposure was associated with a trend to higher creatinine increase (P = 0.067).

CONCLUSIONS

After a median of 5.6 years, subjects initiating ritonavir-boosted darunavir + raltegravir or ritonavir-boosted darunavir + tenofovir disoproxil fumarate/emtricitabine experienced few serious clinical adverse events. Most discontinuations were for reasons unrelated to adverse events or virological failure.

Long-term follow-up of HIV-infected patients on dolutegravir monotherapy

BACKGROUND

In recent years, dolutegravir monotherapy has been explored as a drug-reduced regimen for HIV patients.

METHODS

This was a retrospective observational study, including patients virologically suppressed for ≥6 months, without previous virological failure (VF) under integrase inhibitors (INIs), who had been switched to dolutegravir monotherapy (50 mg/day). The primary aim was to report the proportion of VF at week 48 (W48) and week 96 (W96) of dolutegravir monotherapy. The evolution from baseline to W48 of residual viraemia on ultra-deep sequencing and HIV DNA was also evaluated.

RESULTS

Sixty-one patients were included. Prior to switching to dolutegravir monotherapy, they had a median (IQR) of 15.4 (6.5-19.9) years of antiretroviral exposure, 5.8 (3.2-10.3) years of viral suppression and 687 (461-848) CD4+ cells/mm3. They remained on dolutegravir monotherapy for a median (IQR) of 100 (29-148) weeks. Forty-two out of 61 patients (68.9%) reached W48 and 32 out of 61 patients (52.5%) reached W96. VF occurred in three patients, with the emergence of INI resistance. VF occurred before W24 and in patients pre-exposed to INIs. At W48, the probability of VF (Kaplan-Meier analysis) was 5.6% (95% CI = 1.8%-16.4%). The same result was obtained at W96. Detectable residual viraemia did not increase and median HIV DNA did not change significantly (2.4 log/106 cells at baseline and 2.3 log/106 cells at W48). Dolutegravir plasma concentration was above the IC90 in 41/41 samples, from 22 patients.

CONCLUSIONS

Long-term follow-up showed a low risk of VF under dolutegravir monotherapy, in a selected population of patients with previous long-term virological suppression and low HIV reservoir.

Factors associated with the number of drugs in darunavir/cobicistat regimens

BACKGROUND

Darunavir/cobicistat can be used as mono, dual, triple or more than triple therapy.

OBJECTIVES

To assess factors associated with the number of drugs in darunavir/cobicistat regimens.

METHODS

A nationwide retrospective cohort study of consecutive HIV-infected patients initiating darunavir/cobicistat in Spain from July 2015 to May 2017. Baseline characteristics, efficacy and safety at 48 weeks were compared according to the number of drugs used.

RESULTS

There were 761 patients (75% men, 98% were antiretroviral-experienced, 32% had prior AIDS, 84% had HIV RNA <50 copies/mL and 88% had ≥200 CD4 cells/mm3) who initiated darunavir/cobicistat as mono (n=308, 40%), dual (n=173, 23%), triple (n=253, 33%) or four-drug (n=27, 4%) therapy. Relative to monotherapy, triple therapy was more common in men aged <50 years, with prior AIDS and darunavir plus ritonavir use, and with CD4 cells <200/mm3 and with detectable viral load at initiation of darunavir/cobicistat; dual therapy was more common with previous intravenous drug use, detectable viral load at initiation of darunavir/cobicistat and no prior darunavir plus ritonavir; and four-drug therapy was more common with prior AIDS and detectable viral load at initiation of darunavir/cobicistat. Monotherapy and dual therapy showed a trend to better virological responses than triple therapy. CD4 responses and adverse effects did not differ among regimens.

DISCUSSION

Darunavir/cobicistat use in Spain has been tailored according to clinical characteristics of HIV-infected patients. Monotherapy and dual therapy have been common and preferentially addressed to older patients with a better HIV status, suggesting that health issues other than HIV infection may have been strong determinants of its prescription.

The proximal proteome of 17 SARS-CoV-2 proteins links to disrupted antiviral signaling and host translation

Viral proteins localize within subcellular compartments to subvert host machinery and promote pathogenesis. To study SARS-CoV-2 biology, we generated an atlas of 2422 human proteins vicinal to 17 SARS-CoV-2 viral proteins using proximity proteomics. This identified viral proteins at specific intracellular locations, such as association of accessary proteins with intracellular membranes, and projected SARS-CoV-2 impacts on innate immune signaling, ER-Golgi transport, and protein translation. It identified viral protein adjacency to specific host proteins whose regulatory variants are linked to COVID-19 severity, including the TRIM4 interferon signaling regulator which was found proximal to the SARS-CoV-2 M protein. Viral NSP1 protein adjacency to the EIF3 complex was associated with inhibited host protein translation whereas ORF6 localization with MAVS was associated with inhibited RIG-I 2CARD-mediated IFNB1 promoter activation. Quantitative proteomics identified candidate host targets for the NSP5 protease, with specific functional cleavage sequences in host proteins CWC22 and FANCD2. This data resource identifies host factors proximal to viral proteins in living human cells and nominates pathogenic mechanisms employed by SARS-CoV-2.

Author Summary

SARS-CoV-2 is the latest pathogenic coronavirus to emerge as a public health threat. We create a database of proximal host proteins to 17 SARS-CoV-2 viral proteins. We validate that NSP1 is proximal to the EIF3 translation initiation complex and is a potent inhibitor of translation. We also identify ORF6 antagonism of RNA-mediate innate immune signaling. We produce a database of potential host targets of the viral protease NSP5, and create a fluorescence-based assay to screen cleavage of peptide sequences. We believe that this data will be useful for identifying roles for many of the uncharacterized SARS-CoV-2 proteins and provide insights into the pathogenicity of new or emerging coronaviruses.

Dolutegravir Monotherapy Versus Dolutegravir/Abacavir/Lamivudine for Virologically Suppressed People Living With Chronic Human Immunodeficiency Virus Infection: The Randomized Noninferiority MONotherapy of TiviCAY Trial

BACKGROUND

We investigated whether dolutegravir (DTG) monotherapy could be used to maintain virological suppression in people living with human immunodeficiency virus (HIV) on a successful dolutegravir-based triple therapy.

METHODS

MONCAY (MONotherapy of TiviCAY) was a 48-week, multicentric, randomized, open-label, 12% noninferiority margin trial. Patients with CD4 nadir >100/μL, plasma HIV-1 RNA <50 copies/mL for ≥12 months, and stable regimen with DTG/abacavir (ABC)/lamivudine (3TC) were 1:1 randomized to continue their regimen or to DTG monotherapy. The primary endpoint was the proportion of patients with HIV RNA <50 copies/mL at week 24 in intention-to-treat snapshot analysis. Virologic failure (VF) was defined as 2 consecutive HIV RNA >50 copies/mL within 2 weeks apart.

RESULTS

Seventy-eight patients were assigned to DTG monotherapy and 80 to continue DTG/ABC/3TC. By week 24, 2 patients in the DTG group experienced VF without resistance to the integrase strand transfer inhibitor (INSTI) class; 1 patient discontinued DTG/ABC/3TC due to an adverse event. The success rate at week 24 was 73/78 (93.6%) in the DTG arm and 77/80 (96.3%) in the DTG/ABC/3TC arm (difference, 2.7%; 95% confidence interval [CI], -5.0 to 10.8). During subsequent follow-up, 5 additional VFs occurred in the DTG arm (2 of which harbored emerging resistance mutation to INSTI). The cumulative incidence of VF at week 48 was 9.7% (95% CI, 2.8 to 16.6) in the DTG arm compared with 0% in the DTG/ABC/3TC arm (P = .005 by the log-rank test). The Data Safety Monitoring Board recommended to reintensify the DTG arm with standardized triple therapy.

CONCLUSIONS

Because the risk of VF with resistance increases over time, we recommend avoiding DTG monotherapy as a maintenance strategy among people living with chronic HIV infection.

CLINICAL TRIALS REGISTRATION

NCT02596334 and EudraCT 2015-002853-36.

An apparent paradox: resistance mutations in HIV-1 DNA predict improved virological responses to antiretroviral therapy

BACKGROUND

In sub-Saharan Africa, detecting resistance-associated mutations (RAMs) at failure of first-line ART with two NRTIs plus an NNRTI predicts improved virological responses to second-line therapy with two NRTIs plus a ritonavir-boosted PI (PI/r). This indicates residual NRTI activity in the presence of RAMs, although additional factors may contribute to the effect.

OBJECTIVES

The aim of this study was to investigate the influence of pre-existing RAMs on the outcomes of maintenance monotherapy with ritonavir-boosted darunavir within a randomized trial in Cameroon.

METHODS

RAMs were detected in HIV-1 DNA using PBMCs collected at initiation of darunavir/ritonavir monotherapy. Adherence was assessed by pill count and visual analogue scale (VAS). Predictors of virological failure (confirmed or last available viral load >400 copies/mL) were explored by logistic regression analysis. Trial name = MANET (NCT02155101).

RESULTS

After NNRTI-based therapy, participants (n = 81) had received PI/r-based therapy for a median of 3.2 years and had a confirmed viral load <60 copies/mL and a median CD4 count of 466 cells/mm3. NRTI and NNRTI RAMs were detected in 39/60 (65.0%) and 41/60 (68.3%) HIV-1 DNA sequences, respectively. Over 48 weeks of monotherapy, 16/81 (19.8%) patients experienced virological failure. After adjusting for age, HIV-1 DNA load, adherence by VAS and RAM status, virological failure was less likely with higher VAS-measured adherence (adjusted OR 0.04, 95% CI 0.01-0.37; P = 0.004) and detectable HIV-1 DNA RAMs (adjusted OR 0.15, 95% CI 0.03-0.82; P = 0.028).

CONCLUSIONS

Pre-existing NRTI and NNRTI RAMs are associated with improved virological responses to NRTI-sparing ART in sub-Saharan Africa, indicating a predictive effect that is independent of residual NRTI activity.

Exploration of Reduced Doses and Short-Cycle Therapy for Darunavir/Cobicistat in Patients with HIV Using Population Pharmacokinetic Modeling and Simulations

BACKGROUND AND OBJECTIVES

Protease inhibitors such as darunavir are an important therapeutic option in the anti-human immunodeficiency virus arsenal. Current dosage guidelines recommend using cobicistat- or ritonavir-boosted darunavir 800 mg every 24 h (q24h) in protease inhibitor-naïve patients, or ritonavir-boosted darunavir 600 mg q12h in experienced patients. However, darunavir displays a large, poorly characterized, inter-individual pharmacokinetic variability. The objectives of this study were to investigate the pharmacokinetics of darunavir and to elucidate the sources of its inter-individual variability using population pharmacokinetic modeling. Then, to determine the appropriateness of current treatment guidelines and the feasibility of alternative dosing regimens in a representative cohort of adult patients using simulations.

METHODS

Sparse pharmacokinetic samples were collected in 127 patients with human immunodeficiency virus type 1 infection, then supplemented with rich sampling data from a subset of 12 individuals. Data were analyzed using the nonlinear mixed-effects modeling software NONMEM. The effect of reduced doses (600 mg q24h and 400 mg q24h) or reduced frequency of administration (800 mg q24h for 5 days followed by 2 days of treatment interruption) was simulated.

RESULTS

Our model adequately described the pharmacokinetics of darunavir. Predictors of individual exposure were CYP3A5*3 and SLCO3A1 rs8027174 genotypes, sex, and alpha-1 acid glycoprotein level. No relationship was apparent between darunavir area under the curve and treatment efficacy or safety. For reduced dose regimens, darunavir concentrations remained above the protein binding-corrected EC₅₀ in the majority of subjects. More stringent pharmacokinetic targets were not reached in a significant proportion of patients.

CONCLUSIONS

These results add to the growing body of evidence that darunavir-based therapy could be simplified to reduce costs and toxicity, as well as to improve patient compliance. However, the heterogeneity in pharmacokinetic response should be considered when assessing whether individual patients could benefit from a particular regimen, for instance through the use of population pharmacokinetic models.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03101644, date of registration: 5 April, 2017.

Meta-analysis of noninferiority and equivalence trials: ignoring trial design leads to differing and possibly misleading conclusions

OBJECTIVE

The objective of the study is to examine the analytic approach of meta-analyses that include noninferiority or equivalence (NI/EQ) trials.

STUDY DESIGN AND SETTING

We used Scopus to identify meta-analyses including NI/EQ trials. We extracted data from the meta-analyses and their included randomized clinical trials (RCTs). We used the RCT's NI/EQ margins to reinterpret the results of the meta-analyses, assessed for risk of biases unique to NI/EQ trials, and evaluated the consistency of the meta-analysis interpretation when using NI/EQ margins.

RESULTS

We identified 38 unique meta-analyses including 515 RCTs, of which 125 (24.3%) were NI/EQ trials. Fourteen meta-analyses (36.8%) reported the study design of their included trials, but only one (2.6%) interpreted their pooled estimates using NI/EQ margins and none assessed for risks of bias unique to NI/EQ trials. Nearly all NI/EQ trials (n = 116, 92.8%) included in the meta-analyses reported NI/EQ margins. The meta-analyses of 30 outcomes were reinterpreted using the NI/EQ margins; reinterpretations conflicted with the conclusion of the meta-analyses in most cases (n = 20, 66.7%).

CONCLUSION

Most meta-analyses including NI/EQ trials ignore trial design and do not assess risks of bias unique to NI/EQ studies. Meta-analyses addressing questions previously explored as NI/EQ should conduct an NI/EQ meta-analysis or use clear language when performing standard (i.e., superiority) meta-analyses.

Evolution of Protease Inhibitor Resistance in Human Immunodeficiency Virus Type 1 Infected Patients Failing Protease Inhibitor Monotherapy as Second-line Therapy in Low-income Countries: An Observational Analysis Within the EARNEST Randomized Trial

BACKGROUND

Limited viral load (VL) testing in human immunodeficiency virus (HIV) treatment programs in low-income countries often delays detection of treatment failure. The impact of remaining on failing protease inhibitor (PI)-containing regimens is unclear.

METHODS

We retrospectively tested VL in 2164 stored plasma samples from 386 patients randomized to receive lopinavir monotherapy (after initial raltegravir induction) in the Europe-Africa Research Network for Evaluation of Second-line Therapy (EARNEST) trial. Protease genotypic resistance testing was performed when VL >1000 copies/mL. We assessed evolution of PI resistance mutations from virological failure (confirmed VL >1000 copies/mL) until PI monotherapy discontinuation and examined associations using mixed-effects models.

RESULTS

Median post-failure follow-up (in 118 patients) was 68 (interquartile range, 48-88) weeks. At failure, 20% had intermediate/high-level resistance to lopinavir. At 40-48 weeks post-failure, 68% and 51% had intermediate/high-level resistance to lopinavir and atazanavir; 17% had intermediate-level resistance (none high) to darunavir. Common PI mutations were M46I, I54V, and V82A. On average, 1.7 (95% confidence interval 1.5-2.0) PI mutations developed per year; increasing after the first mutation; decreasing with subsequent mutations (P < .0001). VL changes were modest, mainly driven by nonadherence (P = .006) and PI mutation development (P = .0002); I47A was associated with a larger increase in VL than other mutations (P = .05).

CONCLUSIONS

Most patients develop intermediate/high-level lopinavir resistance within 1 year of ongoing viral replication on monotherapy but retain susceptibility to darunavir. Viral load increased slowly after failure, driven by non-adherence and PI mutation development.

CLINICAL TRIALS REGISTRATION

NCT00988039.

Continuation of emtricitabine/lamivudine within combination antiretroviral therapy following detection of the M184V/I HIV-1 resistance mutation

OBJECTIVES

The aim of the study was to investigate whether lamivudine (3TC) or emtricitabine (FTC) use following detection of M184V/I is associated with better virological outcomes.

METHODS

We identified people with viruses harbouring the M184V/I mutation in UK multicentre data sets who had treatment change/initiation within 1 year. We analysed outcomes of viral suppression (< 200 HIV-1 RNA copies/mL) and appearance of new major drug resistance mutations (DRMs) using Cox and Poisson models, with stratification by new drug regimen (excluding 3TC/FTC) and Bayesian implementation, and estimated the effect of 3TC/FTC adjusted for individual and viral characteristics.

RESULTS

We included 2597 people with the M184V/I resistance mutation, of whom 665 (25.6%) were on 3TC and 458 (17.6%) on FTC. We found a negative adjusted association between 3TC/FTC use and viral suppression [hazard ratio (HR) 0.84; 95% credibility interval (CrI) 0.71-0.98]. On subgroup analysis of individual drugs, there was no evidence of an association with viral suppression for 3TC (n = 184; HR 0.94; 95% CrI 0.73-1.15) or FTC (n = 454; HR 0.99; 95% CrI 0.80-1.19) amongst those on tenofovir-containing regimens, but we estimated a reduced rate of viral suppression for people on 3TC amongst those without tenofovir use (n = 481; HR 0.71; 95% CrI 0.54-0.90). We found no association between 3TC/FTC and detection of any new DRM (overall HR 0.92; 95% CrI 0.64-1.18), but found inconclusive evidence of a lower incidence rate of new DRMs (overall incidence rate ratio 0.69; 95% CrI 0.34-1.11).

CONCLUSIONS

We did not find evidence that 3TC or FTC use is associated with an increase in viral suppression, but it may reduce the appearance of additional DRMs in people with M184V/I. 3TC was associated with reduced viral suppression amongst people on regimens without tenofovir.

HIV Viral Dynamics of Lopinavir/Ritonavir Monotherapy as Second-Line Treatment: A Prospective, Single-Arm Trial

Background:

Characterizing viral response to lopinavir/ritonavir (LPV/r) monotherapy as second-line treatment may guide recommendations for resource-limited settings (RLS).

Methods:

We conducted a 48-week prospective, single-arm study of LPV/r monotherapy in patients failing first-line therapy in Nigeria. The primary outcome was sustained HIV-1 viral load (VL) <400 copies/mL at 48 weeks.

Results:

Of 30 enrolled patients, 28 (93%) achieved viral suppression on LPV/r, while 29 (96%) experienced low-level viremia. At 48 weeks, 9 (30%) met the primary outcome of sustained viral suppression; 14 (47%) patients were suppressed on LPV/r in a snapshot analysis. Detectable VLs at 12 and 24 weeks were strongly associated with treatment failure at 48 weeks. New resistance mutations were not detected. The trial was stopped early due to treatment failure.

Conclusion:

In this study, the rate of virologic failure among patients on a second-line lopinavir monotherapy regimen was relatively high and predicted by early detectable viremia. However, no LPV/r-associated resistance mutations were detected despite fluctuating low-level viremia, demonstrating the high genetic barrier to resistance of the protease inhibitor class which could be useful in RLS.

Cost-Effectiveness Analysis of Lopinavir/Ritonavir Monotherapy Versus Standard Combination Antiretroviral Therapy in HIV-1 Infected Patients with Viral Suppression in France (ANRS 140 DREAM)

BACKGROUND

Protease inhibitor monotherapy is a simplified treatment strategy for virally suppressed HIV-positive patients that has the potential for cost savings, as fewer drugs are used than with combination therapy. However, evidence for its economic value is limited.

OBJECTIVES

We assessed the cost-effectiveness of lopinavir/ritonavir monotherapy followed by treatment intensification in case of viral load rebound versus combination antiretroviral therapy (cART) with efavirenz/emtricitabine/tenofovir in HIV-1 infected patients with viral suppression in the ANRS 140 DREAM trial.

METHODS

DREAM was conducted in 36 French Hospitals between 2009 and 2013. For each treatment strategy, we estimated the unadjusted and multivariate-adjusted mean costs (in €, year 2010 values) and quality-adjusted life-years (QALYs) per patient, as well as incremental costs and QALYs per patient. We then assessed uncertainty using the cost-effectiveness acceptability curve, scenario analyses and cost-effectiveness price-threshold (CEPT) analysis.

RESULTS

In the base-case analysis considering 2009-2013 antiretroviral drug (ARV) prices, adjusted incremental costs and QALYs were - €3296 (95% confidence interval [CI] - 5202 to - 1391) and 0.006 (95% CI - 0.021 to 0.033), respectively, over 2 years, suggesting that monotherapy was cost-effective with a probability of 100% at various cost-effectiveness thresholds. In scenario analyses considering 2018 ARV prices, monotherapy remained cost-effective but with a lower probability (94% vs. 100% in the base-case analysis). The current price of cART would have to decrease by 34% to be cost-effective with a probability of 95%.

CONCLUSION

Monotherapy appears to be cost-effective compared with cART for virologically suppressed HIV-positive patients in France. CEPT analysis is a useful tool to identify the preferred strategy to adopt given that ARV prices change rapidly.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT00946595.

Ultrasensitive Human Immunodeficiency Virus Type 1 Viral Load as a Marker of Treatment Choice for Simplification Strategies

Background

Using 3 randomized Protease inhibitor (PI) monotherapy studies: Kalesolo, Dream and Monoi, we performed a pooled-analysis. Our objective was to determine in PI monotherapy and standard tritherapy: 1) distribution of ultrasensitive viral load (USVL) at week 96 (W96); 2) factors associated with virological failure (VF) at W96 and 3) factors associated with USVL<1 copy at W96.

Methods

VF was defined as 2 consecutive measurements of Human Immunodeficiency Virus Type 1 RNA viral load>50 copies/mL and analysed in Intention-To-Treat. A logistic model was used to investigate which variables were predictive of a VF and Fisher test to investigate differences in USVL at W96.

Results

Among 609 patients, 73% were male with median age of 44.4 years (IQR 39.8-52.1), baseline CD4/CD8 ratio was 0.8 (IQR 0.6-1.10), baseline CD4 was 564.5/mm3 (IQR 422-707) and 59% presented a baseline USVL<1 copy/mL. At W96, the proportion of USVL<1 copy/mL was significantly different between PI monotherapy and standard tritherapy in pooled-analysis (65% versus 74%; p=0.04). Overall, baseline USVL<1copy/mL, tritherapy and to be a female were associated with USVL<1 copy/mL at W96 (p<0.0001, p=0.049 and p=0.006). In PI monotherapy receiving DRV/r was associated with USVL<1 copy/mL at W96 (p=0.003). Factors associated to virological succes at W96 were higher baseline CD4 (p=0.034) and baseline USVL<1 copy/mL (p=0.0005).

Conclusion

Pooled-analysis of 3 PI monotherapy trials showed better efficacy of tritherapy in terms of USVL at W96. Furthermore regarding USVL at W96, to receive LPV/r seems to be more deleterious than DRV/r. Baseline USVL impacts VF at W96 more specifically in tritherapy arm.

Clinical Trials Registration

NCT00421551, NCT00946595, and NCT00140751.

Individual patient data meta-analysis of randomized controlled trials of dual therapy with a boosted PI plus lamivudine for maintenance of virological suppression: GeSIDA study 9717

Background

Dual therapy (DT) with a ritonavir-boosted PI (PI/r) plus lamivudine has proven non-inferior (12% margin) to triple therapy (TT) with PI/r plus two nucleos(t)ide reverse transcriptase inhibitors [N(t)RTIs] in four clinical trials. It remains unclear whether DT is non-inferior based on the US FDA endpoint (virological failure with a margin of 4%) or in specific subgroups.

Methods

We performed a systematic search (January 1990 to March 2017) of randomized controlled trials that compared switching of maintenance ART from TT to DT. The principal investigators were contacted and agreed to share study databases. The primary endpoint was non-inferiority of DT to TT based on the current FDA endpoint (4% non-inferiority margin for virological failure at week 48). We also analysed whether efficacy was modified by gender, active HCV infection and type of PI. Effect estimates and 95% CIs were calculated using generalized estimating equation-based models.

Results

We found 881 references that yielded eight articles corresponding to four clinical trials (1051 patients). At week 48, 4% of patients on DT versus 3.04% on TT had experienced virological failure (difference 0.9%; 95% CI -1.2% to 3.1%), and 84.7% of patients on DT versus 83.2% on TT had <50 copies of HIV RNA/mL (FDA snapshot algorithm) (difference 1.4%; 95% CI -2.8% to 5.8%). Gender, active HCV infection and type of PI had no effect on differences in treatment efficacy between DT and TT.

Conclusions

DT was non-inferior to TT using both current and past FDA endpoints. The efficacy of DT was not influenced by gender, active HCV infection status, or type of PI.

Atazanavir/ritonavir with lamivudine as maintenance therapy in virologically suppressed HIV-infected patients: 96 week outcomes of a randomized trial

Objectives

To investigate the long-term safety and efficacy of a treatment switch to dual ART with atazanavir/ritonavir + lamivudine versus continuing a standard regimen with atazanavir/ritonavir + 2NRTI in virologically suppressed patients.

Methods

ATLAS-M is a 96 week open-label, randomized, non-inferiority (margin -12%) trial enrolling HIV-infected adults on atazanavir/ritonavir + 2NRTI, with stable HIV-RNA <50 copies/mL and CD4 counts >200 cells/mm3. At baseline, patients were randomized 1:1 to switch to atazanavir/ritonavir + lamivudine or to continue the previous regimen. Here, we report the 96 week efficacy and safety data. The study was registered with ClinicalTrials.gov, number NCT01599364.

Results

Overall, 266 subjects were enrolled (133 in each arm). At 96 weeks, in the ITT population, patients free of treatment failure totalled 103 (77.4%) with atazanavir/ritonavir + lamivudine and 87 (65.4%) with triple therapy (difference +12.0%, 95% CI +1.2/+22.8, P = 0.030), demonstrating the superiority of dual therapy. Two (1.5%) and 9 (6.8%) virological failures occurred in the dual-therapy arm and the triple-therapy arm, respectively, without development of resistance to any study drug. Clinical adverse events occurred at similar rates in both arms. A higher frequency of grade 3-4 hyperbilirubinemia (66.9% versus 50.4%, P = 0.006) and hypertriglyceridaemia (6.8% versus 1.5%, P = 0.031) occurred with dual therapy, although this never led to treatment discontinuation. A significant improvement in renal function and lumbar spine bone mineral density occurred in the dual-therapy arm. The evolution of CD4, HIV-DNA levels and neurocognitive performance was similar in both arms.

Conclusions

In this randomized study, a treatment switch to atazanavir/ritonavir + lamivudine was superior over the continuation of atazanavir/ritonavir + 2NRTI in virologically suppressed patients, with a sustained benefit in terms of improved renal function and bone mineral density.

Impact of intensification with raltegravir on HIV-1-infected individuals receiving monotherapy with boosted PIs

Background

Monotherapy with ritonavir-boosted PIs (PI/r) has been used to simplify treatment of HIV-1-infected patients. In previous studies raltegravir intensification evidenced ongoing viral replication and reduced T cell activation, preferentially in subjects receiving PI-based triple ART. However, data about low-level viral replication and its consequences in patients receiving PI/r monotherapy are scarce.

Methods

We evaluated the impact of 24 weeks of intensification with raltegravir on markers of viral persistence, cellular immune activation and inflammation biomarkers in 33 patients receiving maintenance PI/r monotherapy with darunavir or lopinavir boosted with ritonavir. ClinicalTrials.gov identifier: NCT01480713.

Results

The addition of raltegravir to PI/r monotherapy resulted in a transient increase in 2-LTR (long-terminal repeat) circles in a significant proportion of participants, along with decreases in CD8+ T cell activation levels and a temporary increase in the expression of the exhaustion marker CTLA-4 in peripheral T lymphocytes. Intensification with raltegravir also reduced the number of samples with intermediate levels of residual viraemia (10–60 HIV-1 RNA copies/mL) compared with samples taken during PI/r monotherapy. However, there were no changes in cell-associated HIV-1 DNA in peripheral CD4+ T cells or soluble inflammatory biomarkers (CD14, IP-10, IL-6, C-reactive protein and D-dimer).

Conclusions

Intensification of PI/r monotherapy with raltegravir revealed persistent low-level viral replication and reduced residual viraemia in some patients during long-term PI/r monotherapy. The concomitant change in T cell phenotype suggests an association between active viral production and T cell activation. These results contribute to understanding the lower efficacy rates of PI/r monotherapies compared with triple therapies in clinical trials.

Week 96 efficacy of lopinavir/ritonavir monotherapy in virologically suppressed patients with HIV: a randomized non-inferiority trial (ANRS 140 DREAM)

Background

Sparing of antiretroviral drug classes could reduce the toxicity and cost of maintenance treatment for HIV infection.

Objectives

To evaluate the non-inferiority of efficacy and the safety of lopinavir/ritonavir (r) monotherapy versus a single-tablet regimen of efavirenz, emtricitabine and tenofovir (EFV/FTC/TDF) over 2 years.

Methods

Adults on stable ART with plasma HIV-1 RNA viral load <50 copies/mL for the past 12 months and no documented treatment failure were randomized to receive either lopinavir/r or EFV/FTC/TDF for 2 years. The primary endpoint was the proportion of patients without treatment failure at week 96 (viral load <50 copies/mL at week 96, confirmed at week 98), without study treatment discontinuation, a new AIDS-defining illness, or death.

Results

In the ITT analysis, the primary endpoint was reached by, respectively, 64% and 71% of patients in the lopinavir/r (n = 98) and EFV/FTC/TDF arms (n = 97), yielding a difference of -6.8% (lower limit of the 95% two-sided CI: -19.9%). Sanger and UltraDeep sequencing showed the occurrence of PI mutations in the lopinavir/r arm (n = 4) and of NNRTI and/or NRTI mutations in the EFV/FTC/TDF arm (n = 2). No unexpected serious clinical events occurred.

Conclusions

Lopinavir/r monotherapy cannot be considered non-inferior to EFV/FTC/TDF. PI resistance rarely emerged in the lopinavir/r arm and did not undermine future PI options. Two years of lopinavir/r monotherapy had no deleterious clinical impact when compared with EFV/FTC/TDF.

Dolutegravir resistance mutations: lessons from monotherapy studies

PURPOSE OF REVIEW

Dolutegravir (DTG) is a second-generation integrase strand transfer inhibitor (InSTI) with an outstanding antiviral potency, good tolerability, good pharmacokinetic profile with a lack of major drug-drug interactions, and a barrier to resistance higher than the other compounds of the class (raltegravir and elvitegravir) and allegedly as high as that of boosted protease inhibitors. For these reasons, DTG, after successful results in a context of triple therapy in various clinical scenarios, has been investigated mostly by independent investigators in less-drug regimens, including dolutegravir monotherapy, in the context of a growing clinical interest for adjusting successful antiretroviral therapy to the increasing number of limitations for standard antiretroviral therapy in some HIV-infected patients. However, the development of genotypic resistance in case of failure to DTG monotherapy was unexpected.

RECENT FINDINGS

Data on efficacy and resistance from preclinical studies, randomized clinical trials and clinical cohorts of HIV-infected patients treated with DTG monotherapy published in indexed journals or presented at international meetings were reviewed.

SUMMARY

Monotherapy with dolutegravir has a high rate for resistance selection in the integrase gene through different pathways in case of virological failure.

Switching Antiretroviral Therapy in the Setting of Virologic Suppression: A Why and How-To Guide

This review provides a synopsis of key clinical considerations for switching antiretroviral therapy (ART) for individuals with human immunodeficiency virus who have maintained a routinely suppressed viral load. There may be benefits but also risks involved in every ART regimen change, so strategies for prioritizing individuals for a switch based on the specific antiretroviral agents in the regimen are discussed, along with approaches to ensure maintenance of viral suppression after treatment modifications. Controversial and evolving questions in the area of ART switches and simplifications are also considered.

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.

Four-days-a-week antiretroviral maintenance therapy in virologically controlled HIV-1-infected adults: the ANRS 162-4D trial

Background

Intermittent treatment could improve the convenience, tolerability and cost of ART, as well as patients' quality of life. We conducted a 48 week multicentre study of a 4-days-a-week antiretroviral regimen in adults with controlled HIV-1-RNA plasma viral load (VL).

Methods

Eligible patients were adults with VL < 50 copies/mL for at least 1 year on triple therapy with a ritonavir-boosted PI (PI/r) or an NNRTI. The study protocol consisted of the same regimen taken on four consecutive days per week followed by a 3 day drug interruption. The primary outcome was the proportion of participants remaining in the strategy with VL < 50 copies/mL up to week 48. The study was designed to show an observed success rate of > 90%, with a power of 87% and a 5% type 1 error. The study was registered with ClinicalTrials.gov (NCT02157311) and EudraCT (2014-000146-29).

Results

One hundred patients (82 men), median age 47 years (IQR 40-53), were included. They had been receiving ART for a median of 5.1 (IQR 2.9-9.3) years and had a median CD4 cell count of 665 (IQR 543-829) cells/mm3. The ongoing regimen included PI/r in 29 cases and NNRTI in 71 cases. At 48 weeks, 96% of participants (95% CI 90%-98%) had no failure while remaining on the 4-days-a-week regimen. Virological failure occurred in three participants, who all resumed daily treatment and became resuppressed. One participant stopped the strategy. No severe treatment-related events occurred.

Conclusions

Antiretroviral maintenance therapy 4 days a week was effective for 48 weeks in 96% of patients, leading to potential reduction of long-term toxicities, high adherence to the antiretroviral regimen and drug cost saving.

Simplification of combination antiretroviral therapy (cART) and the brain-a real-life experience

Modern antiretroviral combination therapy (cART) has transformed HIV from a life-threatening infection into a chronic disease. However, the life-long treatment has side effects that frequently have a negative impact on patients' quality of life. Thus, there are some efforts to "simplify" therapy, i.e. apply regimens with three or fewer antiretroviral substances. However, neurologists are relatively sceptical towards this cART "simplification", because the capacity of simplified regimens to access the cerebrospinal fluid (CSF) might be too weak to effectively suppress viral load in this compartment. Thus, data of a big Neuro-AIDS cohort of 4992 HIV-positive patients consecutively recruited over three decades were retrospectively analysed in terms of neurocognitive performance of patients switched to simplified therapy regimens. To test whether simplified drug regimens result in new neuropsychological deficits or the worsening of pre-existing ones in HIV+ patients. Three groups of HIV+ patients were switched from triple therapy to three different two drug regimens (n = 177 to lamivudine/PI, n = 37 to INI/PI, and n = 303 to dual PI); three other groups of patients put from one to an alternative triple combination (n = 290 ABC/3TC/PI, n = 244 TDF/FTC/PI, and n = 158 TDF/FTC/NNRTI) for whatever reason served as controls. All patients were followed up over 4 years maximum. Every patient group improved immunologically and virologically after the switch. However, patients who switched to INI/PI combinations remained stable in neuropsychological tests, while a considerable percentage of patients who switched to other treatments demonstrated a decline. Remarkably, a high percentage of the patients switched to "simplified drug regimens" was not well-controlled virologically before the switch. HIV-positive patients with simplified therapy regimens show some benefit in terms of systemic infection surrogate markers (CD4 ± cell count and plasma viral load); however, neurocognitive deficits do not improve, but remain stable in most cases.

Darunavir/cobicistat maintains the effectiveness of darunavir/ritonavir in HIV-infected patients under mono or dual therapy

OBJECTIVES

Darunavir/ritonavir (DRV/r) in mono or dual therapy has proven efficacy in selected patients. The aim of this study was to evaluate the efficacy of switching from DRV/r to DRV/cobicistat (DRV/c) in patients under mono or dual therapy.

METHODS

This was a prospective multicenter cohort study of patients using DRV/r under mono or dual therapy plus lamivudine who changed to DRV/c maintaining the previous regimen. All patients had a controlled HIV viral load (<50 copies/ml) when switched and were examined every 12 weeks. The primary end-point was the percentage of participants without virological failure (VF) at week 48 in the intent-to-treat analysis. The CD4 cell count and concentrations of cholesterol, triglyceride, and creatinine were measured from baseline to week 48.

RESULTS

A total of 162 patients were included: 68.5% were men, and their mean age was 46 ± 12 years. Seventy (43.2%) patients were treated with DRV/r monotherapy, and 92 (56.8%) were treated with DRV/r plus lamivudine. The efficacy at week 48 was 95.1% (95% CI: 90.6%-97.5%) in the intent-to-treat analysis and 98.7% (95.5-99.6%) in the on-treatment analysis. Two VFs were documented but without development of resistance mutations. No significant changes were found in the lipid profile. Creatinine concentration increased significantly by 0.07 mg/dl (0.04-0.10, P < 0.001).

CONCLUSIONS

Switching from DRV/r to DRV/c in patients under mono or dual therapy is safe and effective.

Effect of mono/dual antiretroviral therapy on suppression of HCV and HIV during treatment of HCV infection in HIV/HCV-coinfected patients

OBJECTIVE

Data of hepatitis C treatment with direct-acting antivirals (DAAs) in HIV infected patients are limited to a few number of antiretroviral therapies (ART). The aim of this study was to assess the effectiveness and safety of non-conventional ART as monotherapy or dual therapy (MDT) when combined with DAA.

METHODS

Retrospective review of HIV/HCV-coinfected patients treated with DAAs during one year in 3 centers. Sustained virologic response 12 weeks after therapy (SVR) and maintenance of HIV viral suppression were compared between patients receiving triple ART (TT) or MDT.

RESULTS

Overall 485 patients were included (359 receiving TT and 126 MDT). HCV SVR was 93.4% (95%CI, 90.8% to 95.3%) in the intention-to-treat analysis without differences between groups: 92.8% on TT vs 95.2% on MDT (p=0.3). HCV virological failure was associated with lower CD4+cell count at baseline (for every 100-cell/μl increment: OR, 0.8; 95%CI, 0.7-0.9; p=0.01) and with liver stiffness (for every 10-unit increment: OR, 1.5; 95%CI 1.2-1.8; p<0.01). HIV-RNA during HCV treatment or 12 weeks after was detectable in 23 patients on TT (6.6%) and 9 (7.2%) patients on MDT (p=0.8). The median (IQR) change in CD4+cell count was not significantly different between the groups: 15 (-55 to 115) in TT vs -12 (-68 to 133) cells/μl in MDT (p=0.8).

CONCLUSION

DAAs obtain high rates of SVR among HIV/HCV-coinfected patients independently of whether TT or non-conventional ART is used. Suppression of HIV was maintained in both groups.

HIV Cerebrospinal Fluid Escape and Neurocognitive Pathology in the Era of Combined Antiretroviral Therapy: What Lies Beneath the Tip of the Iceberg in Sub-Saharan Africa?

Neurocognitive impairment remains an important HIV-associated comorbidity despite combination antiretroviral therapy (ART). Since the advent of ART, the spectrum of HIV-associated neurocognitive disorder (HAND) has shifted from the most severe form to milder forms. Independent replication of HIV in the central nervous system despite ART, so-called cerebrospinal fluid (CSF) escape is now recognised in the context of individuals with a reconstituted immune system. This review describes the global prevalence and clinical spectrum of CSF escape, it role in the pathogenesis of HAND and current advances in the diagnosis and management. It highlights gaps in knowledge in sub-Saharan Africa where the HIV burden is greatest and discusses the implications for this region in the context of the global HIV treatment scale up.

Impact of Antiretroviral Regimens on Cerebrospinal Fluid Viral Escape in a Prospective Multicohort Study of Antiretroviral Therapy-Experienced Human Immunodeficiency Virus-1-Infected Adults in the United States

Background

Cerebrospinal fluid (CSF) viral escape occurs in 4%-20% of human immunodeficiency virus (HIV)-infected adults, yet the impact of antiretroviral therapy (ART) on CSF escape is unclear.

Methods

A prospective study of 1063 participants with baseline plasma viral load (VL) ≤400 copies/mL between 2005 and 2016. The odds ratio (OR) for ART regimens (protease inhibitor with nucleoside reverse transcriptase inhibitor [PI + NRTI] vs other ART) and CSF escape was estimated using mixed-effects models.

Results

Baseline mean age was 46 years, median plasma VL, and CD4 count were 50 copies/mL, and 424 cells/μL, respectively. During median follow-up of 4.4 years, CSF escape occurred in 77 participants (7.2%). PI + NRTI use was an independent predictor of CSF escape (OR, 3.1; 95% confidence interval, 1.8-5.0) in adjusted analyses and models restricted to plasma VL ≤50 copies/mL (P < .001). Regimens that contained atazanavir (ATV) were a stronger predictor of CSF viral escape than non-ATV PI + NRTI regimens. Plasma and CSF M184V/I combined with thymidine-analog mutations were more frequent in CSF escape vs no escape (23% vs 2.3%). Genotypic susceptibility score-adjusted central nervous system (CNS) penetration-effectiveness (CPE) values were calculated for CSF escape with M184V/I mutations (n = 34). Adjusted CPE values were low (<5) for CSF in 27 (79%), indicating suboptimal CNS drug availability.

Conclusions

PI + NRTI regimens are independent predictors of CSF escape in HIV-infected adults. Reduced CNS ART bioavailability may predispose to CSF escape in patients with M184V/I mutations.

Dual antiretroviral therapy with tenofovir (TDF) and darunavir/ritonavir (DRV/RTV) in an HIV-1 positive patient: a case report, review, and meta-analysis of the literature on dual treatment strategies using protease inhibitors in combination with an NRTI

BACKGROUND

Here, we report the case of an HIV positive patient under a dual antiretroviral drug regimen with tenofovir disoproxil and darunavir/ritonavir with stable clinical, virological, and immunological response over 126 weeks. Dual antiretroviral therapy has the advantage of reduced toxicity and lower health care costs, treatment failure and fostering drug resistance are perceived risks. Optimal drug combinations and indication criteria for dual treatment remain controversial. Nevertheless, first clinical trials indicate non-inferiority for combinations of nucleoside reverse transcriptase inhibitors and protease inhibitors. This case presents the combination of tenofovir disoproxil in combination with a protease inhibitor as a new potential dual treatment regimen.

METHOD

We performed a systematic literature search and meta-analysis of trials comparing dual to triple ART.

RESULTS

Literature review revealed nine studies in which dual therapy with a protease inhibitor and an NRTI was compared to triple therapy. We performed a meta-analysis of six trials that reported a 48-week follow-up. In treatment-naïve patients as well when ART switch was assessed, there was no difference in the treatment success in patients with dual ART versus triple.

CONCLUSION

We conclude that dual therapy with a protease inhibitor and NRTI is safe and effective. The use of tenofovir in dual treatment as described in our case needs to be assessed in future clinical trials.

Effect of monotherapy with darunavir/cobicistat on viral load and semen quality of HIV-1 patients

Many patients previously using darunavir/ritonavir (DRV/r) (800/100mg) have switched to darunavir/cobicistat (DRV/C) (800/150 mg) either as part of triple therapy (ART) or as monotherapy with DRV (mDRV). The latter approach continues to be used in some countries for patients receiving long-term treatment. However, to date, the behaviour of DRV/C in the seminal compartment has not been analysed. This study explores how the combination behaves in monotherapy, with respect to the control of viral load and seminal quality. To this end, we studied 20 patients who were treated with mDRV/C after previous treatment with mDRV/r for at least 24 weeks. A viral load control in seminal plasma similar to that published in the literature was observed after 24 weeks of treatment with mDRV/C (viral load positivity in 20% of patients). Similarly, semen quality was confirmed (70% normozoospermic) in patients treated with this formulation, as has previously been reported for ART and mDRV/r. The DRV levels measured in seminal plasma were above EC50, regardless of whether the seminal viral load was positive or negative. We conclude that this mDRV/C co-formulation behaves like mDRV/r in seminal plasma in terms of viral load control and semen quality.

Cerebrospinal fluid drug concentrations and viral suppression in HIV-1-infected patients receiving ritonavir-boosted atazanavir plus lamivudine dual antiretroviral therapy (Spanish HIV/AIDS Research Network, PreEC/RIS 39)

This study aimed to assess cerebrospinal fluid (CSF) drug concentrations and viral suppression in HIV-1-infected patients on ritonavir-boosted atazanavir (ATV/r) plus lamivudine (3TC) dual therapy. HIV-1-infected adults with suppressed plasma HIV-1 RNA who switched to ATV/r plus 3TC were studied. Total ATV and 3TC concentrations at the end of the dosing interval (C_24h), using a validated LC-MS/MS method, and HIV-1 RNA were measured in paired CSF and plasma samples 12 weeks after switching. Ten individuals were included. Median (range) age was 42.5 (33-70) years, time on ART was 39.5 (11-197) months, and time with plasma HIV-1 RNA < 40 copies/mL was 15.5 (6-46) months. At baseline, CSF HIV-1 RNA was < 40 copies/mL in all patients. Twelve weeks after switching to ATV/r plus 3TC, HIV-1 RNA remained at < 40 copies/mL in both plasma and CSF in 9/10 patients. One patient with suboptimal adherence to ART had HIV-1 RNA rebound in both plasma and CSF. The median CSF-to-plasma concentration ratios of ATV and 3TC were 0.013 and 0.417, respectively. Median ATV C_24h in CSF was 10.4 (3.7-33.4) ng/mL (in vitro ATV IC₅₀ range, 1-11 ng/mL). Median 3TC C_24h in CSF was 43.4 (16.2-99.3) ng/mL (in vitro 3TC IC₅₀ range, 0.68-20.6 ng/mL). Most patients maintained HIV-1 RNA in CSF < 40 copies/mL despite CSF ATV C_24h close to or within the IC₅₀ range in the majority. ATV PK data in CSF should be considered and rigorous patient selection is advisable to assure effective CSF viral suppression with this two-drug simplification regimen.

Next generation sequencing of HIV-1 protease in the PIVOT trial of protease inhibitor monotherapy

•

Next generation sequencing (NGS) was performed on patients on PI monotherapy.

•

It revealed previously unidentified minority variant protease mutations in 3 samples.

•

These mutations do not predict clinically important phenotypic resistance.

Background

The PIVOT trial examined whether patients with suppressed viral load on combination antiretroviral therapy could be safely switched long-term to ritonavir-boosted protease inhibitor (PI) monotherapy. The main trial publication reported that only one of 296 patients allocated to PI monotherapy experienced a loss of drug options due to protease mutations (identified by local Sanger sequencing resistance tests) likely selected by study drug.

Objectives

To assess if we had missed low frequency mutations, using a more sensitive methodology.

Study design

We performed next generation sequencing (NGS) on all available frozen plasma samples with VL >1000 copies/ml from patients who were randomised to PI monotherapy. Assays were performed at Public Health England laboratories using a previously described method.

Median coverage depth was 76,000 and the threshold for detection of minority variants was 2%. Drug susceptibility was predicted using the Stanford HIVdb algorithm.

Results

17 of 26 potential samples, all from different patients, were identified and successfully tested. The median viral load was 6780 copies/ml and the median time since randomisation was 43 weeks. NGS revealed previously unidentified minority variant protease mutations (G73D, I54T, L89V) in three samples, at frequencies ranging between 2% and 10%. None of these mutations predicted intermediate or high level resistance, the trial primary outcome.

Discussion

This report adds to the body of evidence that ritonavir-boosted PI monotherapy, when used as a switch strategy with prompt detection of viral load rebound and early re-introduction of combination therapy, rarely leads to the development of clinically important protease resistance mutations.

Darunavir/cobicistat showing similar effectiveness as darunavir/ritonavir monotherapy despite lower trough concentrations

INTRODUCTION

When darunavir (DRV) 800 mg is boosted with 150 mg cobicistat (DRVcobi ), DRV trough concentration (Ctrough ) is about 30% lower as compared to 100 mg ritonavir (DRVrtv ). DRVcobi shows similar virological efficacy as DRVrtv when combined with two nucleos(t)ide analogue reverse-transcriptase inhibitors, but it is unknown whether a lower DRV Ctrough would undermine the effectiveness of DRVcobi when given as monotherapy (mtDRVcobi ).

METHODS

Prospective observational study on virologically suppressed HIV-infected subjects who switched to mtDRVcobi . Virological failure was defined as two consecutive HIV-RNA >200 copies/mL. Efficacy was evaluated by intention-to-treat (ITT) and on-treatment (OT) analyses, and compared with data from a previous cohort of subjects on mtDRVrtv conducted at our centre. Plasma DRV Ctrough was measured using LC-MS/MS.

RESULTS

A total of 234 subjects were enrolled. At week 96, the efficacy rates were 67.8% (CI95 , 61.8 to 73.7) by ITT and 86.9% (CI95 , 78.0 to 87.7) by OT analyses. The corresponding rates in our historical DRVrtv controls were 67.6% (CI95 , 60.0 to 75.2) and 83.6% (CI95 : 77.2 to 90.0). A total of 135 DRV determinations were performed in 83 subjects throughout the follow-up period, with a median plasma DRV Ctrough of 1305 ng/mL (range, 150 to 5895) compared with 1710 ng/mL (range, 200 to 3838) in subjects on monotherapy with DRVrtv (p = 0.05).

CONCLUSIONS

DRV Ctrough was lower in HIV-infected subjects receiving DRVcobi than with DRVrtv . However, this did not appear to influence the efficacy of DRVcobi , when administered as monotherapy.

Simplification to dual-therapy containing lamivudine and darunavir/ritonavir or atazanavir/ritonavir in HIV-infected patients on virologically suppressive antiretroviral therapy

BACKGROUND

The ritonavir-boosted protease inhibitor (PI/r)-based dual regimens are warranted in order to optimize the combination antiretroviral therapy (cART), prevent the long-term toxicity and reduce the cost of treatments.

METHODS

We performed an observational, retrospective study of HIV-infected patients on suppressive antiretroviral therapy who switched to a dual regimen containing lamivudine (3TC) plus darunavir/ritonavir (DRV/r) 800/100 mg qd or atazanavir/ritonavir (ATV/r) 300/100 mg qd.

RESULTS

As a whole, 122 well-treated patients (mean age, 45.2 years; mean CD4 T + lymphocyte count, 589 cells/mm³; mean duration of current cART, 3.1 years) were enrolled. Current antiretroviral regimen included tenofovir/emtricitabine in 91 subjects, abacavir/lamivudine in 25, lopinavir/r in 41, DRV/r in 38 and ATV/r in 33. Baseline mean estimated glomerular filtration rate (eGFR) was 94.2 mL/min/1.73 m², and proteinuria was detected in 46 subjects (38%). Overall 70 subjects switched to 3TC + DRV/r (group A) and 52 to 3TC + ATV/r (group B). After 12 months, 65 patients (92.8%) in group A and 46 (88.4%) in group B showed HIV RNA <20 copies/mL. A significant and comparable increase in eGFR was observed in group A and B (+3.8 and +3.1 mL/min/1.73 m², respectively), such as a significant decrease in prevalence of proteinuria. A significantly greater increase in total bilirubin concentration was reported in group B than in group A.

CONCLUSION

In our study, simplification to a dual therapy containing 3TC + DRV/r or ATV/r in virologically suppressed patients was effective and showed a good tolerability profile.

HIV-1 resistance rarely observed in patients using darunavir once-daily regimens across clinical studies

BACKGROUND

Darunavir 800 mg once daily (QD) is indicated for HIV-1-infected treatment-naïve and treatment-experienced (without darunavir resistance-associated mutations [RAMs]) individuals, and has been evaluated in phase 2/3 studies with durations between 48 and 192 weeks.

OBJECTIVE

To summarize the development (or identification) of post-baseline resistance (RAMs and antiretroviral phenotypic susceptibility) among patients receiving darunavir QD dosing.

METHODS

Seven phase 2/3 studies with available genotypes/phenotypes for subjects treated with ritonavir- or cobicistat-boosted darunavir 800 mg QD regimens were assessed: ARTEMIS (NCT00258557; n = 343), GS-US-299-0102 (NCT01565850; n = 153), GS-US-216-0130 (NCT01440569; n = 313), ODIN (NCT00524368; n = 294), INROADS (NCT01199939; n = 54), MONET (NCT00458302; n = 256), and PROTEA (NCT01448707; n = 273). Genotypic analyses were conducted at baseline (except switch studies enrolling virologically suppressed subjects [MONET, PROTEA]). Criteria for post-baseline resistance testing and evaluation of the development (or identification [switch studies]) of RAMs (respective IAS-USA mutations) varied slightly across studies.

RESULTS

Among 1686 subjects treated with darunavir 800 mg QD regimens, 184 had protocol-defined virologic failure; 182 had post-baseline genotypes analyzed. Overall, 4/1686 (0.2%) developed (or had identified [switch studies]) primary protease inhibitor and/or darunavir RAMs (ARTEMIS, n = 1; GS-US-216-0130, n = 1; ODIN, n = 1; MONET, n = 1). Only 1/1686 (<0.1%) subject lost darunavir phenotypic susceptibility (ODIN; possibly related to prior ritonavir-boosted lopinavir virologic failure). Among 1103 subjects using a nucleos(t)ide reverse transcriptase inhibitor (N[t]RTI) backbone, 10 (0.9%) developed ≥ 1 N(t)RTI RAM (8 had the emtricitabine RAM M184I/V).

CONCLUSIONS

Darunavir has a high genetic barrier to resistance. Across a diverse population of HIV-1-infected subjects treated with darunavir 800 mg QD regimens, the development of darunavir resistance was rare (<0.1%).

Dolutegravir as maintenance monotherapy for HIV (DOMONO): a phase 2, randomised non-inferiority trial

BACKGROUND

The high genetic barrier to resistance of dolutegravir might allow for its use as maintenance monotherapy in patients with HIV. We investigated whether dolutegravir monotherapy was non-inferior to combination antiretroviral therapy (ART) for maintaining virological suppression in patients with HIV-1 infection successfully treated with combination ART.

METHODS

We did this open-label, phase 2, randomised non-inferiority trial at two medical centres in the Netherlands. Eligible patients (aged ≥18 years) were on combination ART, had been virologically suppressed (HIV RNA <50 copies per mL) for at least 6 months, and had CD4 nadirs of 200 cells per μL or higher, HIV RNA zeniths of 100 000 copies per mL or less, and no history of virological failure. Patients were randomly assigned (1:1), via a web-based block randomisation method (variable block sizes of 4 and 6), to switch to dolutegravir monotherapy (50 mg once a day) either immediately or after a delay of 24 weeks of continued combination ART. Randomisation was stratified by HIV RNA zenith (<50 000 copies per mL vs 50 000-99 999 copies per mL). Investigators and patients were not masked to group allocation. The primary endpoint was the proportion of patients with plasma HIV RNA viral loads of less than 200 copies per mL at week 24, with a non-inferiority margin of 12%. We did analyses in the on-treatment and intention-to-treat populations. This trial is registered with ClinicalTrials.gov, NCT02401828.

FINDINGS

Between March 10, 2015, and Feb 4, 2016, we randomly assigned 51 patients to the immediate switch group and 53 patients to the delayed switch group. One patient who received immediate monotherapy discontinued treatment at week 12 because of disturbed sleep. At week 24, dolutegravir monotherapy was non-inferior to combination ART, with plasma HIV RNA loads of 200 copies per mL or higher observed in 2% (1/50) of patients in the immediate switch group and in no patients in the delayed switch group (difference 2%, 95% CI -5 to 12). Of patients assigned to the delayed switch group, 47 (89%) switched to dolutegravir monotherapy at week 24, two (4%) of whom subsequently discontinued monotherapy because of headache (n=1) and disturbed sleep (n=1). Eight (8%) of the 95 patients who remained on dolutegravir monotherapy had virological failure; all had therapeutic plasma concentrations of dolutegravir. In three (38%) of the eight patients, mutations associated with resistance were detected in the integrase gene. According to a predefined stopping rule, detection of these mutations led to premature study discontinuation.

INTERPRETATION

Dolutegravir monotherapy was non-inferior to combination ART at 24 weeks. However, virological failure continued to occur thereafter and led to dolutegravir resistance. Dolutegravir should not be used as maintenance monotherapy.

FUNDING

Erasmus Trustfonds.

Fetal Metabolic Stress Disrupts Immune Homeostasis and Induces Proinflammatory Responses in Human Immunodeficiency Virus Type 1- and Combination Antiretroviral Therapy-Exposed Infants

Increased morbidity and fetal growth restriction are reported in uninfected children born to human immunodeficiency virus type 1 (HIV-1)-infected women treated with antiretroviral (ARV) therapy. Viruses and/or pharmacological interventions such as ARVs can induce metabolic stress, skewing the cell's immune response and restricting (cell) growth. Novel metabolomic techniques provided the opportunity to investigate the impact of fetal HIV-1 and combination ARV therapy (cART) exposure on the infants' immune metabolome. Peroxidized lipids, generated by reactive oxygen species, were increased in cART/HIV-1-exposed infants, indicating altered mitochondrial functioning. The lipid metabolism was further dysregulated with increased triglyceride species and a subsequent decrease in phospholipids in cART/HIV-1-exposed infants compared to control infants. Proinflammatory immune mediators, lysophospholipids as well as cytokines such as CXCL10 and CCL3, were increased whereas anti-inflammatory metabolites from the cytochrome P450 pathway were reduced in cART/HIV-1-exposed infants. Taken together, these data demonstrate that the fetal metabolism is impacted by maternal factors (cART and HIV-1) and skews physiological immune responses toward inflammation in the newborn infant.

Treatment simplification to atazanavir/ritonavir + lamivudine versus maintenance of atazanavir/ritonavir + two NRTIs in virologically suppressed HIV-1-infected patients: 48 week results from a randomized trial (ATLAS-M)

Background

Combination ART (cART)-related toxicities and costs have prompted the need for treatment simplification. The ATLAS-M trial explored 48 week non-inferior efficacy of simplification to atazanavir/ritonavir  +  lamivudine versus maintaining three-drug atazanavir/ritonavir-based cART in virologically suppressed patients.

Methods

We performed an open-label, multicentre, randomized, non-inferiority study, enrolling HIV-infected adults on atazanavir/ritonavir + two NRTIs, with stable HIV-RNA <50 copies/mL and CD4 + >200 cells/mm 3 . Main exclusion criteria were hepatitis B virus coinfection, past virological failure on or resistance to study drugs, recent AIDS and pregnancy. Patients were randomly assigned 1:1 to either switch to 300 mg of atazanavir/100 mg of ritonavir once daily and 300 mg of lamivudine once daily (atazanavir/ritonavir + lamivudine arm) or to continue the previous regimen (atazanavir/ritonavir + two NRTIs arm). The primary study outcome was the maintenance of HIV-RNA <50 copies/mL at week 48 of the ITT-exposed (ITT-e) analysis with switch = failure. The non-inferiority margin was 12%. This study is registered at ClinicalTrials.gov, number NCT01599364.

Results

Between July 2011 and June 2014, 266 patients were randomized (133 to each arm). After 48 weeks, the primary study outcome was met by 119 of 133 patients (89.5%) in the atazanavir/ritonavir + lamivudine arm and 106 of 133 patients (79.7%) in the atazanavir/ritonavir + two NRTIs arm [difference atazanavir/ritonavir + lamivudine versus atazanavir/ritonavir + two NRTIs arm: +9.8% (95% CI + 1.2 to + 18.4)], demonstrating non-inferiority and superior efficacy of the atazanavir/ritonavir + lamivudine arm. Virological failure occurred in two (1.5%) patients in the atazanavir/ritonavir + lamivudine arm and six (4.5%) patients in the atazanavir/ritonavir + two NRTIs arm, without resistance selection. A similar proportion of adverse events occurred in both arms.

Conclusions

Treatment simplification to atazanavir/ritonavir + lamivudine showed non-inferior efficacy (superiority on post-hoc analysis) and a comparable safety profile over continuing atazanavir/ritonavir + two NRTIs in virologically suppressed patients.

Impact of monotherapy on HIV-1 reservoir, immune activation, and co-infection with Epstein-Barr virus

Objectives

Although monotherapy (mART) effectiveness in maintaining viral suppression and CD4 cell count has been extensively examined in HIV-1-infected patients, its impact on HIV-1 reservoir, immune activation, microbial translocation and co-infection with Epstein-Barr Virus (EBV) is unclear.

Methods

This retrospective study involved 32 patients who switched to mART; patients were studied at baseline, 48 and 96 weeks after mART initiation. Thirty-two patients who continued combined antiretroviral therapy (cART) over the same period of time were included in the study. Markers of HIV-1 reservoir (HIV-1 DNA and intracellular HIV-1 RNA) were quantified by real-time PCR. Markers of T-(CD3⁺CD8⁺CD38⁺) and B-(CD19⁺CD80/86⁺ and CD19⁺CD10^-CD21^lowCD27⁺) cell activation were evaluated by flow cytometry. Plasma levels of microbial translocation markers were quantified by real-time PCR (16S ribosomal DNA and mitochondrial [mt]DNA) or by ELISA (LPS and sCD14). EBV was typed and quantified by multiplex real-time PCR.

Results

At baseline, no differences were found between mART and cART groups. Three (10%) mART-treated patients had a virological failure vs none in the cART group. Levels of HIV-1 DNA, intracellular HIV-1 RNA and EBV-DNA remained stable in the mART group, while decreased significantly in the cART group. Percentages of T- and B-activated cells significantly increased in the mART-treated patients, while remained at low levels in the cART-treated ones (p = 0.014 and p<0.001, respectively). Notably, levels of mtDNA remained stable in the cART group, but significantly rose in the mART one (p<0.001).

Conclusions

Long-term mART is associated with higher levels of T- and B-cell activation and, conversely to cART, does not reduce the size of HIV-1 reservoir and EBV co-infection.

Novel approaches to HIV therapy

There are approximately 35 million people infected by human immunodeficiency virus (HIV), with an estimated 2 million incident infections annually across the globe. While HIV infection was initially associated with high rates of morbidity and mortality, advances in therapy have transformed it into a chronic and manageable disease. In addition, there is very strong evidence that those on antiretroviral therapy are much less likely to transmit infection to their partners. The success rates for maintaining viral suppression in treated patients has dramatically increased owing to the development of agents that are potent and well tolerated and can often be co-formulated into single pills for simplification. This review will outline advances in treatment over the last several years as well as new strategies that may shift the existing treatment paradigm in the near future.

Treating HIV Infection in the Central Nervous System

Combination antiretroviral treatment is associated with clear benefits in HIV-positive subjects, and is also effective in the central nervous system (CNS), meaning HIV-associated dementia is now an uncommon event. Nevertheless, a significant number of patients show symptoms of neurocognitive impairment which may negatively affect their quality of life. Although several risk factors for HIV-associated neurocognitive disorders have been identified, there is no clear recommendation for their prevention and management. In this review, the penetration of drugs into the cerebrospinal fluid/CNS is discussed as well as the viral and clinical consequences associated with higher/lower compartmental exposure. We also review the potential interventions according to the currently identified underlying mechanisms, including persistent CNS immune activation, legacy effects, low-level viral replication and escape, co-morbidities, and antiretroviral-associated direct and indirect 'neurotoxicity'. Adjunctive therapies and interventions (including neuro-rehabilitation) are then briefly discussed. The treatment of HIV infection in the CNS is a complex area of therapeutics requiring multidisciplinary interventions and further study.

Refining criteria for selecting candidates for a safe lopinavir/ritonavir or darunavir/ritonavir monotherapy in HIV-infected virologically suppressed patients

Objective

The primary objective of this study was to estimate the incidence of treatment failure (TF) to protease inhibitor monotherapies (PI/r-MT) with lopinavir/ritonavir (LPV/r) or darunavir/ritonavir (DRV/r).

Design

A multicenter cohort of HIV-infected patients with viral load (VL) ≤50 copies/mL, who underwent a switch from any triple combination therapy to PI/r-MT with either LPV/r or DRV/r.

Methods

VL was assessed in each center according to local procedures. Residual viremia was defined by any HIV-RNA value detectable below 50 copies/mL by a Real-Time PCR method. Standard survival analysis was used to estimate the rate of TF (defined by virological failure or interruption of monotherapy or reintroduction of combination therapy). A multivariable Cox regression analysis with automatic stepwise procedures was used to identify factors independently associated with TF among nadir and baseline CD4+ counts, residual viremia, time spent with <50 HIV-RNA copies/mL before switch, history of virological failure, HCV co-infection, being on a PI/r and hemoglobin concentrations at baseline.

Results

Six hundred ninety patients fulfilled the inclusion criteria and were included in this analysis. Their median follow-up was 20 (10–37) months. By month 36, TF occurred in 176 (30.2%; 95% CI:25.9–34.5) patients. Only CD4+ nadir counts (adjusted hazard ratio [aHR] = 2.03 [95% CI: 1.35, 3.07] for counts ≤100 vs. >100 cells/μL) and residual viremia (aHR = 1.48 [95% CI: 1.01–2.17] vs. undetectable VL) were independently associated to TF.

Conclusions

Residual viremia and nadir CD4+ counts <100 cells/μL should be regarded as the main factors to be taken into account before considering switching to a PI/r-MT.

Atherogenic properties of LDL particles after switching from Truvada or Kivexa plus lopinavir/r to lamivudine plus lopinavir/r: OLE-MET substudy

BACKGROUND

The objective of this study was to determine the impact of tenofovir or abacavir discontinuation on low-density lipoprotein (LDL) phenotype and lipoprotein-associated phospholipase A2 (Lp-PLA2) activity in HIV-infected patients treated with lopinavir/ritonavir plus 2 nucleos(t)ide reverse transcriptase inhibitors (NRTI).

METHODS

Multicenter, open-label study. Patients were randomized to continue with lopinavir/ritonavir plus 2 NRTI (triple therapy) or to switch to lopinavir/ritonavir plus lamivudine (dual therapy). LDL phenotype (by gradient gel electrophoresis) and Lp-PLA2 (by 2-thio-PAF) were determined at baseline and week 48.

RESULTS

Forty-four patients included (triple therapy n = 19, dual therapy n = 25): men 63.6%, age 41.5 years (25-61), Framingham score 4.9% (0.2-22). Tenofovir was part of the regimen in 28 (63.6%) patients. Dual therapy patients were younger (p = 0.013) and had lower baseline apolipoprotein A1 (p = 0.029). At week 48, there were no changes in standard lipid measurements, except ApoA1/Apo B, which increased in dual therapy (p = 0.038) with no differences between arms. At week 48, no change in LDL phenotype was found in either arm. No changes in total Lp-PLA2 activity or the relative distribution of LDL and HDL particles were found at week 48 in either arm.

CONCLUSIONS

Discontinuing the third nucleos(t)ide, mainly tenofovir and abacavir, in a lopinavir/ritonavir-containing regimen was not associated with a deleterious effect on LDL phenotype nor in Lp-PLA2 activity.