Efficacy of a nucleoside-sparing regimen of darunavir/ritonavir plus raltegravir in treatment-naive HIV-1-infected patients (ACTG A5262)

Effects of switching to dolutegravir/lamivudine from tenofovir alafenamide fumarate/emtricitabine/dolutegravir or abacavir/lamivudine/dolutegravir on body weight and lipid profile in Japanese people living with HIV

BACKGROUND

The two-drug regimen of dolutegravir/lamivudine (DTG/3TC) is currently an optional antiretroviral therapy (ART). Despite its reported advantages on body weight and lipid profile, the same effects have not yet been reported for Asian population.

METHODS

We conducted a single-center retrospective study involving Japanese people living with HIV (PLWH). They were divided into four groups: those who had received abacavir/lamivudine/dolutegravir (ABC/3TC/DTG) and continued the same (ABC-ON group) or switched to DTG/3TC (ABC-OFF group), those who had received tenofovir alafenamide fumarate/emtricitabine/dolutegravir (TAF/FTC/DTG) and continued the same (TAF-ON group) or switched to DTG/3TC (TAF-OFF group). We compared changes in viral load, CD4⁺ cell count, CD4⁺/CD8⁺ ratio, body weight, BMI, lipid profiles, estimated glomerular filtration rate (eGFR), and fibrosis index based on four factors (FIB4-index) between the pre-switch and post-switch period.

RESULTS

Of the 541 PLWH on DTG-based ART, 165, 94, 264 and 18 constituted the ABC-ON, ABC-OFF, TAF-ON, and TAF-OFF groups, respectively. Neither viral rebound nor CD4+decline was observed in the post-switch period in all groups. Multivariate analysis showed significant reduction in total cholesterol, LDL-C and HDL-C in the ABC-OFF group (-6.280, -6.957 and -2.268, p = 0.040, 0.012 and 0.022, respectively), but not in the TAF-OFF group (-3.000, 6.708 and 0.046, p = 0.607, 0.276 and 0.983, respectively). No significant changes were observed in body weight, eGFR, or FIB4-index at 72 weeks after the discontinuation of ABC or TAF.

CONCLUSIONS

Switching from ABC/3TC/DTG to DTG/3TC lowered lipids significantly, but not with TAF/FTC/DTG. Neither switch affected body weight or other markers.

Outcome of Darunavir-Cobicistat-Based Regimens in HIV-Infected People Who Have Experienced Virological Failure

Objective

To evaluate the virological outcome of darunavir-cobicistat (DRVc)-based regimens in adults living with HIV who had experienced virological failure (VF) on any previous drug combination.

Methods

This was a retrospective cohort study (CSLHIV Cohort) of adults living with HIV who started a DRVc-based regimen with HIV-RNA >50 copies/mL after VF on any previous drug combination. Data on demographics, antiretroviral treatment since HIV diagnosis, and immunological and metabolic parameters from baseline (start of DRVc) to 48 weeks were analyzed in order to assess the cumulative proportion of those who achieved virological success (VS), defined as at least one instance of HIV-RNA <50 copies/mL within 12 months from baseline. Follow-up lasted from the start of the DRVc-based regimen (baseline) to the first instance of HIV-RNA <50 copies/mL, last available visit, or loss to follow-up or death, whichever occurred first. Univariate and multivariate Cox proportional-hazard regression models were used to identify baseline factors associated with VS.

Results

A total of 176 individuals were included, and 120 (68.2%) achieved <50 HIV-RNA copies/mL within 12 months since baseline. On multivariate analysis, baseline HDL cholesterol was independently associated with the occurrence of VS (adjusted HR 1.021, 95% CI 1.004-1.038; p=0.014). Among the 120 subjects with VS, 27 (22.5%) had had VF during a median follow-up of 20.8 months since the first undetectable HIV-RNA. Resistance testing after VF was available in two cases, which harboured the HIV variant-bearing protease inhibitor-resistance mutations D30N, I50V, and N88D. During a median follow-up of 38.4 months, 65 of 176 (36.9%) individuals discontinued DRVc for any reason (37 of 120, 30.8%) and achieved VS vs. 28 of 56 (50%) without VS (p=0.019). Time to discontinuation was longer in people with VS (41.5 vs. 23.0 months, p=0.0007). No statistically significant changes were observed in immunological or lipid profiles during follow-up.

Conclusion

Most individuals in this study achieved VS within 12 months from the beginning of a DRVc-based regimen; therefore, this treatment represent a viable option for people who have experienced VF on other regimens.

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.

Evaluation of treatment efficacy after switching to dolutegravir-lamivudine dual therapy in people living with HIV

Background

People living with HIV need to use antiretroviral therapy throughout their lives.

Objectives

Studies on the efficacy and safety of dual therapy are limited in Turkey. We sought to evaluate the treatment efficacy and side effects among patients who were given a combination of dolutegravir (DTG) and lamivudine (3TC) as a maintenance therapy.

Methods

This retrospective, single-centre study included individuals with viral suppression who were older than 18 years of age, living with HIV, switched from a combination antiretroviral therapy regimen to DTG-3TC dual therapy, and followed up for at least 6 months.

Results

The study included 63 patients living with HIV. The median age was 42 years (interquartile range (IQR): 36-51 years). The median follow-up under the DTG-3TC regimen was 10.4 months (7.1-16.0 months). In the course of dual therapy, no patients developed any serious adverse effects that would necessitate a therapy switch, but virological blips were seen in two patients. Two patients lost their lives, with one dying from suicide and one dying from respiratory failure associated with the underlying chronic obstructive pulmonary disease.

Conclusion

The DTG-3TC dual-therapy regimen is a promising and effective therapy that can be used as a treatment of choice for eligible patients.

Characteristics of 2-drug regimen users living with HIV-1 in a real-world setting: A large-scale medical claim database analysis in Japan

Background

Regimen simplification to 2-drug antiretroviral therapy (2-ART) may address potential tolerability issues, increase adherence, and reduce toxicity and potential drug-drug-interactions among people living with HIV-1 (PLWH). However, real-world treatment patterns and characteristics of 2-ART users are unclear.

Methods

This retrospective observational cohort study employed a large-scale medical claim database of Japanese hospitals to extract data on 4,293 PLWH aged ≥18 years with diagnosis of HIV and treated with any ART regimens between April 2008 and April 2019. A 2-ART cohort was compared with a 3-drug antiretroviral therapy (3-ART) cohort in terms of population characteristics, comorbid conditions, and treatment patterns. Treatment switching rates were calculated for each cohort followed by sensitivity analysis to confirm the robustness of the findings.

Results

There were 94 individuals identified in the 2-ART cohort. Compared to the standard 3-ART cohort (n = 3,993), the 2-ART cohort was older (median age 53 [IQR 44–64] vs 42 years [IQR 35–50]), with a lower proportion of males (87.2% vs 93.8%), higher Charlson Comorbidity Index (CCI) (median score 6 [IQR 5–8] vs 5 [IQR 4–6]), more co-medications (median 6 [IQR 4–11] vs 3 [IQR 2–7]), and a higher percentage of AIDS-defining conditions (66.0% vs 42.8%). The most common 2-ART were protease inhibitor (PI) + integrase strand transfer inhibitor (INSTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) + INSTI (33.0% and 31.9%, respectively). Overall, most of the regimens were nucleoside reverse transcriptase inhibitor (NRTI)-sparing (71.3%), with a decreasing trend over time (76.2% to 70.2%). ART regimen switch occurred more often in the 2-ART cohort than in the 3-ART cohort (33.0% vs 21.2%).

Conclusion

The profiles of individuals on 2-ART in Japan were demonstrated to be complex. Most were treated with NRTI-sparing regimens which may reflect an effort to reduce treatment-related toxicities.

Low-level viremia in treated HIV-1 infected patients: advances and challenges

Antiretroviral therapy (ART) can effectively suppress HIV-1 replication, improving quality of life and restoring the lifespan of persons living with HIV (PLWH) to near normal levels. However, after standardized ART, a low level of HIV-1 RNA, i.e., low-level viremia (LLV), may still be identified in 3% to 10% of the patients. LLV is capable of impacting the immunological and clinical outcome of patients and serves as a risk factor for transmission. The underlying mechanism of LLV is not yet certain, and the effects of LLV on patient outcomes remain under evaluation. Understanding LLV will allow effective prevention and control strategies to be designed for the benefit of PLWH.

Two-Drug Regimens for HIV-Current Evidence, Research Gaps and Future Challenges

During the last 30 years, antiretroviral treatment (ART) for human immunodeficiency virus (HIV) infection has been continuously evolving. Since 1996, three-drug regimens (3DR) have been standard-of-care for HIV treatment and are based on a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus two nucleoside reverse transcriptase inhibitors (NRTIs). The effectiveness of first-generation 3DRs allowed a dramatic increase in the life expectancy of HIV-infected patients, although it was associated with several side effects and ART-related toxicities. The development of novel two-drug regimens (2DRs) started in the mid-2000s in order to minimize side effects, reduce drug-drug interactions and improve treatment compliance. Several clinical trials compared 2DRs and 3DRs in treatment-naïve and treatment-experienced patients and showed the non-inferiority of 2DRs in terms of efficacy, which led to 2DRs being used as first-line treatment in several clinical scenarios, according to HIV clinical guidelines. In this review, we summarize the current evidence, research gaps and future prospects of 2DRs.

HIV-1 Gag gene mutations, treatment response and drug resistance to protease inhibitors: A systematic review and meta-analysis protocol

BACKGROUND

Some mutations in the HIV-1 Gag gene are known to confer resistance to ritonavir-boosted protease inhibitors (PI/r), but their clinical implications remain controversial. This review aims at summarizing current knowledge on HIV-1 Gag gene mutations that are selected under PI/r pressure and their distribution according to viral subtypes.

MATERIALS AND METHODS

Randomized and non-randomized trials, cohort and cross-sectional studies evaluating HIV-1 Gag gene mutations and protease resistance associated mutations, will all be included. Searches will be conducted (from January 2000 onwards) in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Latin American and Caribbean Health Sciences Literature (LILAC), Web of Science, African Journals Online, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Hand searching of the reference lists of relevant reviews and trials will be conducted and we will also look for conference abstracts. Genotypic profiles of both Gag gene and the protease region as well as viral subtypes (especially B vs. non B) will all serve as comparators. Primary outcomes will be the "prevalence of Gag mutations" and the "prevalence of PI/r resistance associated mutations". Secondary outcomes will be the "rate of treatment failure" and the distribution of Gag mutations according to subtypes. Two reviewers will independently screen titles and abstracts, assess the full texts for eligibility, and extract data. If data permits, random effects models will be used where appropriate. This study will be reported according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta Analyses.

DISCUSSION

This systematic review will help identify HIV-1 Gag gene mutations associated to PI/r-based regimen according to viral subtypes. Findings of this review will help to better understand the implications of the Gag gene mutations in PI/r treatment failure. This may later justify considerations of Gag-genotyping within HIV drug resistance interpretation algorithms in the clinical management of patients receiving PI/r regimens.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42019114851.

Nucleos(t)ide reverse transcriptase inhibitor-sparing regimens in the era of standard 3-drug combination therapies for HIV-1 infection

Nucleos(t)ide reverse transcriptase inhibitor (NRTI)-sparing regimens have often been selected as antiretroviral therapy (ART) for HIV-1 infection recently, but data for characteristics have been lacking. This study aimed to document the current status of NRTI-sparing regimens in the era of standard 3-drug combination therapies. We cross-sectionally compared characteristics of patients treated with NRTI-sparing regimens (NRTI-sparing group) with dolutegravir plus tenofovir alafenamide fumarate/emtricitabine as a standard ART group in 2018. The NRTI-sparing and the standard ART groups included 61 and 469 patients, respectively. The mean (± standard deviation) age and serum creatinine of the NRTI-sparing group were significantly higher than those of the standard ART group (57.6 ± 12.8 years vs 42.8 ± 10.4 years (p < 0.05) and 2.09 ± 3.10 mg/dL vs. 0.93 ± 0.19 mg/dL (p < 0.05), respectively. The percentage of patients with NRTI-sparing regimens increased with age; with less than 5% in their 50s or younger, 8.4% in their 60s, and 14.1% aged ≥ 70 years. The primary reason for switching to the NRTI-sparing regimen was due to reduced renal function. According to the limited data, viral suppression was achieved at week 48 in all patients in the NRTI-sparing group. No patient had treatment failure nor developed drug resistance. The use of NRTI-sparing regimens increased with age. They were more frequently used in patients aged ≥ 60 years and those with decreased renal function.

Clinical outcomes of two-drug regimens vs. three-drug regimens in antiretroviral treatment-experienced people living with HIV

BACKGROUND

Limited data exist comparing clinical outcomes of two-drug regimens (2DRs) and three-drug regimens (3DRs) in people living with HIV.

METHODS

Antiretroviral treatment-experienced individuals in RESPOND switching to a new 2DR or 3DR from 1/1/12-1/10/18 were included. The incidence of clinical events (AIDS, non-AIDS cancer, cardiovascular disease, end-stage liver and renal disease, death) was compared between regimens using Poisson regression.

RESULTS

Of 9791 individuals included, 1088 (11.1%) started 2DRs and 8703 (88.9%) 3DRs. The most common 2DRs were dolutegravir plus lamivudine (22.8%) and raltegravir plus boosted darunavir (19.8%); the most common 3DR was dolutegravir plus 2 nucleoside reverse transcriptase inhibitors (46.9%). Individuals on 2DRs were older (median 52.6 years [interquartile range 46.7-59.0] vs 47.7 [39.7-54.3]), and a higher proportion had ≥1 comorbidity (81.6% vs 73.9%).There were 619 events during 27,159 person-years of follow-up (PYFU): 540 (incidence rate [IR] 22.5/1000 PYFU [95% CI 20.7-24.5]) on 3DRs, 79 (30.9/1000 PYFU [24.8-38.5]) on 2DRs. The most common events were death (7.5/1000 PYFU [95% CI 6.5-8.6]) and non-AIDS cancer (5.8/1000 PYFU [4.9-6.8]). After adjustment for baseline demographic and clinical characteristics, there was a similar incidence of events on both regimen types (2DRs vs 3DRs IR ratio: 0.92 [0.72-1.19]; p=0.53).

CONCLUSIONS

This is the first large, international cohort assessing clinical outcomes on 2DRs. After accounting for baseline characteristics, there was a similar incidence of events on 2DRs and 3DRs. 2DRs appear to be a viable treatment option with regard to clinical outcomes; further research on resistance barriers and long-term durability of 2DRs is needed.

Brief Report: Virologic Response by Baseline Viral Load With Dolutegravir Plus Lamivudine vs Dolutegravir Plus Tenofovir Disoproxil Fumarate/Emtricitabine: Pooled Analysis

BACKGROUND

To investigate antiviral potency of the 2-drug regimen (2DR) dolutegravir plus lamivudine vs the 3-drug regimen (3DR) dolutegravir plus tenofovir disoproxil fumarate/emtricitabine, we performed a post-hoc analysis assessing antiviral response rates in the phase III GEMINI-1 and GEMINI-2 studies by baseline viral load (VL).

SETTING

One hundred ninety-two centers in 21 countries.

METHODS

Treatment-naive HIV-1-infected participants with screening VL ≤500,000 copies/mL were randomized 1:1 to once-daily dolutegravir plus lamivudine or dolutegravir plus tenofovir disoproxil fumarate/emtricitabine. Median change from baseline was determined for log10-transformed VL in the overall study population and the subpopulation with baseline VL >100,000 copies/mL. Proportion of participants achieving plasma VL <50 copies/mL (Snapshot algorithm) or <40 copies/mL (Abbott RealTime HIV-1 assay) and target not detected was assessed through week 48 by baseline VL. Time to viral suppression was determined (nonparametric Kaplan-Meier method).

RESULTS

For 293 participants with baseline VL >100,000 copies/mL, median change from baseline at week 4 was -3.38 and -3.40 log10 copies/mL in the 2DR and 3DR groups, respectively; reduction was sustained throughout 48 weeks. Time to VL <50 copies/mL was longer in participants with baseline VL >100,000 copies/mL than the overall study population (57 [week 8] vs 29 days [week 4]) and similar between the 2DR and 3DR groups. Proportion of participants with VL <50 or <40 copies/mL and target not detected was similar between groups, irrespective of baseline VL, at all tested visits throughout 48 weeks.

CONCLUSION

Dolutegravir plus lamivudine demonstrates high antiviral potency in treatment-naive HIV-1-infected individuals across baseline VL strata.

Boosted darunavir and dolutegravir dual therapy among a cohort of highly treatment-experienced individuals

BACKGROUND

The use of dual antiretroviral therapy (ART) regimens for treatment of HIV is increasing. The contemporary combination of boosted darunavir with dolutegravir has not been widely studied.

METHODS

This was a retrospective cohort study that evaluated treatment-experienced individuals within three large urban clinics prescribed boosted darunavir with dolutegravir (study regimen) dual therapy. Follow-up was defined as the number of days from regimen initiation until the last HIV RNA determination on the study regimen. Virological outcomes, HIV RNA ≤50 copies/ml (undetectable), were assessed overall and by baseline HIV RNA status.

RESULTS

Of 65 individuals included, 83% were at least 3-class antiretroviral-experienced and median time since starting ART was 19 years (IQR 13-22). Median follow-up was 419 days (IQR 286-744). An undetectable HIV RNA was achieved by 62/65 (95%) individuals at any time point on the study regimen. At the end of follow-up 61/65 (94%) individuals remained undetectable, including 48/49 (98%) with an undetectable HIV RNA at baseline (those changing for optimization) and 13/16 (81%) with viraemia at baseline (those changing therapy during virological failure). At the end of follow-up, 55 (85%) individuals were still taking the study regimen. No individuals stopped therapy due to virological failure or intolerance.

CONCLUSIONS

In a highly treatment-experienced cohort, boosted darunavir with dolutegravir dual therapy demonstrated high rates of virological success, even in those with detectable HIV RNA prior to initiating the study regimen. Further study of this potent, simple, high-barrier dual-class regimen is warranted.

Two-drug regimens with dolutegravir plus rilpivirine or lamivudine in HIV-1 treatment-naïve, virologically-suppressed patients: Latest evidence from the literature on their efficacy and safety

OBJECTIVES

In the HIV-1-positive population, a paradigm shift from three-drug regimens (3DRs) to dolutegravir-based two-drug regimens (2DRs) both as initial and switch treatment is beginning to take place, supported virologically by the availability of new potent drugs with high genetic barrier to overcome, at least in certain conditions, the dogma of 3DRs in effective HIV-1 therapy. This manuscript reviews the increasing evidence on their excellent and sustained long-term effectiveness and safety.

METHODS

This review includes the most recent results on dolutegravir plus rilpivirine or lamivudine 2DRs from randomised clinical trials, meta-analyses and real-life studies, including relevant data presented at international conferences up to August 2019.

RESULTS

As an initial treatment strategy, dolutegravir plus lamivudine showed high efficacy and safety over 96 weeks in 1441 patients from the GEMINI-1&2 phase III non-inferiority trials. In the SWORD 1&2 trials in virologically-suppressed patients, switching to once-daily dolutegravir plus rilpivirine maintained efficacy over 148 weeks. Similarly, in the TANGO trial, no confirmed virological withdrawals were observed with dolutegravir/lamivudine through Week 48. Consistent results were observed in real-life cohorts. No emergent dolutegravir-resistant virus has ever been reported in a patient in whom dolutegravir was prescribed in the context of such 2DRs. Switching to once-daily dolutegravir plus rilpivirine or lamivudine was generally well tolerated and was associated with favourable renal and bone safety.

CONCLUSION

The results available so far support dolutegravir-based 2DRs as excellent treatment options for adults with HIV-1 infection, either naïve or already virologically suppressed on their current antiretroviral regimen.

Comparable viral decay with initial dolutegravir plus lamivudine versus dolutegravir-based triple therapy

OBJECTIVES

To expand understanding of the virological potency of initial dolutegravir plus lamivudine dual therapy (dolutegravir/lamivudine), we compared the viral decay seen in the pilot ACTG A5353 study with the decay observed with dolutegravir plus two NRTIs in the SPRING-1 and SINGLE studies, while also exploring the impact of baseline viral load (VL).

METHODS

Change in VL from baseline was calculated for timepoints shared by A5353 (n = 120, including 37 participants with pretreatment VL >100000 copies/mL), SPRING-1 (n = 51) and SINGLE (n = 417). The 95% CIs of change from baseline were determined for each observed week, using the mean log10-transformed VL, and compared between the dolutegravir/lamivudine and triple therapy groups using the Wilcoxon Rank Sum test for non-inferiority (δ = 0.5). To assess the impact of baseline VL on viral decay, we examined a bi-exponential non-linear mixed-effect model.

RESULTS

The mean VL change from baseline to week 24 was -2.9 log10 copies/mL for dolutegravir/lamivudine versus -3.0 log10 copies/mL for dolutegravir-based three-drug therapy (P < 0.001). In the decay model, baseline VL >100000 copies/mL was associated with a slower initial decay rate (d1). A faster initial decay rate was seen with dolutegravir/lamivudine, which was partially offset when baseline VL was >100000 copies/mL as indicated by a significant interaction between baseline VL and drug therapy group. The secondary decay rate (d2) was not significantly different from zero, with no significant associations.

CONCLUSIONS

Viral decay with dolutegravir/lamivudine was comparable to viral decay with dolutegravir-based triple therapy, even in individuals with higher pretreatment VL (>100000 copies/mL).

Decreased darunavir concentrations during once-daily co-administration with maraviroc and raltegravir: OPTIPRIM-ANRS 147 trial

Background

The OPTIPRIM-ANRS 147 trial compared intensive combination ART (darunavir/ritonavir, tenofovir disoproxil fumarate/emtricitabine, raltegravir and maraviroc) started early during primary HIV-1 infection with standard tritherapy with darunavir/ritonavir, tenofovir disoproxil fumarate and emtricitabine. From month 6 to 18, the percentage of viral load values <50 copies/mL was lower in the pentatherapy arm than in the tritherapy arm. Here we compared antiretroviral drug concentrations between the two arms.

Methods

Plasma samples were collected from 50 patients at various times after drug administration. A Bayesian approach based on published population pharmacokinetic models was used to estimate residual drug concentrations (Ctrough) and exposures (AUC) in each patient. A mixed linear regression model was then used to compare the AUC and Ctrough values of each drug used in both groups.

Results

Published models adequately described our data and could be used to predict Ctrough and AUC. No significant difference in tenofovir disoproxil fumarate, emtricitabine and ritonavir parameters was found between the two arms. However, darunavir Ctrough and AUC were significantly lower in the pentatherapy arm than in the tritherapy arm (P = 0.03 and P = 0.04, respectively).

Conclusions

Adding maraviroc and raltegravir to darunavir-based tritherapy decreased darunavir concentrations. Compliance issues, maraviroc-darunavir interaction and raltegravir-darunavir interaction were suspected and may affect the kinetics of viral decay during pentatherapy. A specific pharmacokinetic interaction study is needed to explore the interactions between darunavir and maraviroc and raltegravir.

Mutations in the HIV-1 envelope glycoprotein can broadly rescue blocks at multiple steps in the virus replication cycle

The p6 domain of HIV-1 Gag contains highly conserved peptide motifs that recruit host machinery to sites of virus assembly, thereby promoting particle release from the infected cell. We previously reported that mutations in the YPX_nL motif of p6, which binds the host protein Alix, severely impair HIV-1 replication. Propagation of the p6-Alix binding site mutants in the Jurkat T cell line led to the emergence of viral revertants containing compensatory mutations not in Gag but in Vpu and the envelope (Env) glycoprotein subunits gp120 and gp41. The Env compensatory mutants replicate in Jurkat T cells and primary human peripheral blood mononuclear cells, despite exhibiting severe defects in cell-free particle infectivity and Env-mediated fusogenicity. Remarkably, the Env compensatory mutants can also rescue a replication-delayed integrase (IN) mutant, and exhibit reduced sensitivity to the IN inhibitor Dolutegravir (DTG), demonstrating that they confer a global replication advantage. In addition, confirming the ability of Env mutants to confer escape from DTG, we performed de novo selection for DTG resistance and observed resistance mutations in Env. These results identify amino acid substitutions in Env that confer broad escape from defects in virus replication imposed by either mutations in the HIV-1 genome or by an antiretroviral inhibitor. We attribute this phenotype to the ability of the Env mutants to mediate highly efficient cell-to-cell transmission, resulting in an increase in the multiplicity of infection. These findings have broad implications for our understanding of Env function and the evolution of HIV-1 drug resistance.

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.

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.

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.

Darunavir concentration in PBMCs may be a better indicator of drug exposure in HIV patients

PURPOSE

The clinical efficacies of some antiretroviral drugs are known to not depend on its concentration in blood. To establish a method of dosage adjustment for darunavir (DRV) based on pharmacokinetic theory, we analyzed the correlation between DRV levels in peripheral blood mononuclear cells (PBMCs) and plasma.

METHODS

The concentrations of DRV and ritonavir (RTV) in plasma and PBMCs of 31 samples obtained from 19 patients were analyzed. An in vitro kinetic study using MOLT-4 cells was performed to assess the contribution of RTV to the intracellular accumulation of DRV.

RESULTS

DRV levels in PBMCs varied between 7.91 and 29.36 ng/10⁶ cells (CV 37.5%), while those in plasma were greater. No significant correlation was found between the trough level of DRV in plasma and that in PBMCs (p = 0.575). The inter-day difference in DRV levels in PBMCs seemed smaller than that in plasma (- 41.6-23.0% vs - 83.3-109.1%). In the in vitro study, the elimination half-life of cellular efflux of DRV was 15.7 h in the absence of RTV and extended to 47.6 h in the presence of RTV.

CONCLUSIONS

We found a poor correlation between intracellular DRV and plasma DRV levels in patients receiving highly active antiretroviral therapy. The efflux rate of DRV from cells was slow; therefore, the concentration of DRV in PBMCs may reflect average exposure to the drug and clinical efficacy.

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.

Gp41 and Gag amino acids linked to HIV-1 protease inhibitor-based second-line failure in HIV-1 subtype A from Western Kenya

Introduction

Failure of protease‐inhibitor (PI)‐based second‐line antiretroviral therapy (ART) with medication adherence but no protease drug resistance mutations (DRMs) is not well understood. This study investigated the involvement of gp41 and gag as alternative mechanisms, not captured by conventional resistance testing and particularly relevant in resource‐limited settings where third‐line ART is limited.

Methods

We evaluated gp41 and gag for unique amino acids in seven subtype A infected Kenyans failing second‐line therapy with no PI resistance yet detectable lopinavir (query dataset), compared to seven similar‐setting patients with PI resistance or undetectable lopinavir and 69 publically available subtype A Kenyan whole‐genomes sequences.

Results

Three gp41 (607T, 641L, 721I) and four gag (124S, 143V, 339P, 357S) amino acids were significantly more frequent in the query dataset compared to the other datasets, with significantly high co‐occurrence.

Conclusion

The genotypic analysis of a unique group of HIV‐1 subtype A infected patients, identified seven amino acids that could potentially contribute to a multi‐gene mechanism of PI‐based ART failure in the absence of PI DR mutations.

Association between depressive symptoms, CD4 count and HIV viral suppression among HIV-HCV co-infected people

Depressive symptoms are associated with poor HIV viral control and immune recovery among people living with HIV. However, no prior studies assessed this association exclusively among people co-infected with HIV-hepatitis C virus (HCV). While people with HIV only and those with HIV-HCV co-infection share many characteristics, co-infected people may become more susceptible to the effects of depressive symptoms on health outcomes. We assessed this association exclusively among people co-infected with HIV-HCV in Canada using data from the Food Security & HIV-HCV Sub-Study (FS Sub-Study) of the Canadian Co-Infection Cohort (CCC). Stabilized inverse probability weighted marginal structural model was used to account for potential time-varying confounders. A total of 725 participants were enrolled between 2012 and 2015. At baseline, 52% of participants reported depressive symptoms, 75% had undetectable HIV viral load, and median CD4 count was 466 (IQR 300-665). People experiencing depressive symptoms had 1.32 times (95% CI: 1.07, 1.63) the risk of having detectable HIV viral load, but had comparable CD4 count to people who did not experience depressive symptoms (fold change of CD4 = 0.96, 95% CI: 0.91, 1.03). Presence of depressive symptoms is a risk factor for incomplete short-term HIV viral suppression among people co-infected with HIV-HCV. Therefore, depressive symptoms screening and related counseling may improve HIV related health outcomes and reduce HIV transmission.

Where are we with injectables against HIV infection and what are the remaining challenges?

INTRODUCTION

Drug adherence has been a recurring issue in the field of HIV treatment, and low treatment adherence is typically associated with emergence of drug resistance, treatment failure and increased risks of transmission. Injectable antiretroviral drugs offer a unique opportunity to counter this issue for the treatment of HIV-positive individuals. In addition, injectables offer a remarkable opportunity to reduce new HIV infections, if applied in the context of both treatment-as-prevention and pre-exposure prophylaxis. Areas covered: Researchers and drug companies are developing long-acting agents that possess long biological half-life and excellent pharmacokinetic profiles that can be administered intramuscularly, intravenously, or subcutaneously. These long-acting injectables are categorized as drugs that target different steps of HIV replication cycle or monoclonal antibodies that target HIV entry. Expert commentary: Injectables against HIV have the potential to revolutionize the fight against HIV by facilitating both treatment and prevention in a wide variety of clinical settings. Several challenges remain including the identification of potent two-drug combinations of drugs that can be formulated as injectables, and thorough drug-drug interaction studies with a broad variety of medications. Finally we believe that the healthcare benefits of injectables will require regulatory changes to allow self-injection before they reach their full potential.

Pharmacokinetics and pharmacodynamics of the nucleoside sparing dual regimen containing rilpivirine plus darunavir/ritonavir in treatment-naïve HIV-1-infected individuals

BACKGROUND

We aimed at investigating the antiviral activity and the pharmacokinetics of the dual antiretroviral (ARV) combination of rilpivirine plus darunavir/ritonavir 25/800/100 mg once-daily in naïve HIV-1-infected individuals (NHII) with different baseline viral loads.

SETTINGS

Pharmacokinetic/pharmacodynamics study in ARV-naïve HIV-infected individuals.

METHODS

The primary endpoint was the number of NHII with HIV-RNA < 40 copies/mL at week 48. Secondary endpoints included rilpivirine/darunavir/ritonavir pharmacokinetics, HIV-RNA decay, and changes in ECG QT interval.

RESULTS

Thirty-six individuals were enrolled, 18 with a baseline viral load < 100,000 copies/mL (group A) and 18 with a baseline viral load > 100,000 copies/mL (group B). All but 1 (HIV-RNA = 63 copies/mL) subjects achieved viral load < 50 copies/mL by week 36, and all at week 48. Median (range) HIV-RNA reduction (Log10 copies/mL) was 1.3 (0.6-1.9) over the first week, with no differences between groups A and B. Geometric mean and 95%CI rilpivirine C_max, C_trough, AUC were 183 (165-239), 114 (104-109) ng/mL, 2966 (2704-3820) ng h/mL. No QTcF interval changes were recorded.

CONCLUSIONS

rilpivirine/darunavir/ritonavir could be efficacious, with limited short-term toxicity in ARV-naïve patients. Although rilpivirine was co-administered with ritonavir, its exposure was within ranges measured during phase III trials.

Food insecurity may lead to incomplete HIV viral suppression and less immune reconstitution among HIV/hepatitis C virus-coinfected people

OBJECTIVES

The aim of this study was to determine the impact of food insecurity (FI) on HIV viral load and CD4 count among people coinfected with HIV and hepatitis C virus (HCV).

METHODS

This study was conducted using data from the Food Security & HIV-HCV Sub-Study of the Canadian Co-Infection Cohort study. FI was measured using the adult scale of Health Canada's Household Food Security Survey Module and was classified into three categories: food security, moderate food insecurity and severe food insecurity. The association between FI, HIV viral load, and CD4 count was assessed using a stabilized inverse probability weighted marginal structural model.

RESULTS

A total of 725 HIV/HCV-coinfected people with 1973 person-visits over 3 years of follow-up contributed to this study. At baseline, 23% of participants experienced moderate food insecurity and 34% experienced severe food insecurity. The proportion of people with undetectable HIV viral load was 75% and the median CD4 count was 460 [interquartile range (IQR): 300-665] cells/μL. People experiencing severe food insecurity had 1.47 times [95% confidence interval (CI): 1.14, 1.88] the risk of having detectable HIV viral load and a 0.91-fold (95% CI: 0.84, 0.98) increase in CD4 count compared with people who were food secure.

CONCLUSIONS

These findings provide evidence of the negative impact of food insecurity on HIV viral load and CD4 count among HIV/HCV-coinfected people.

Efficacy of switching to dolutegravir plus rilpivirine, the small-tablet regimen, in patients with dysphagia: two case reports

BACKGROUND

The advent of well-tolerated and effective anti-retroviral drugs against human immunodeficiency virus-1 (HIV-1) infection has been a major step forward that has achieved long-term survival in recent years. The number of HIV-1 infected patients who experience difficulty in swallowing tablets is expected to increase as the HIV-infected population advances in age or develops comorbidities or treatment sequelae affecting the central nervous system.

CASE PRESENTATION

Here, we describe two HIV-1-infected patients who experienced progressive dysphagia leading to inability to swallow the antiretroviral tablets included in the standard regimen. Both patients had a plasma viral load < 40 copies/mL while receiving anti-retroviral therapy with the recommended combination antiretroviral therapy (cART) regimen, but the dysphagia necessitated a switch. By switching to much smaller sized combined regimen of dolutegravir (DTG) plus rilpivirine (RPV) tablets, both of our patients were able to successfully continue treatment and maintain adherence without the need for crushing tablets or preparing an oral suspension. Additionally, switching from the recommended cART regimen to DTG plus RPV successfully maintained viral suppression. At the last available follow-up (12 months after switching to DTG/RPV), HIV-1 viral load remained below the lower limit of quantification.

CONCLUSIONS

An alternative therapeutic option that takes tablet size into consideration could not only contribute to improved patient adherence, but also a reduced care burden for HIV-infected patients with dysphagia. Thus, switching to the "small-tablet regimen" of DTG plus RPV has the potential to improve the survival and well-being of patients with dysphagia.

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.

Effect of therapy switch on time to second-line antiretroviral treatment failure in HIV-infected patients

BACKGROUND

Switch from first line antiretroviral therapy (ART) to second-line ART is common in clinical practice. However, there is limited knowledge of to which extent different reason for therapy switch are associated with differences in long-term consequences and sustainability of the second line ART.

MATERIAL AND METHODS

Data from 869 patients with 14601 clinical visits between 1999-2014 were derived from the national cohort database. Reason for therapy switch and viral load (VL) levels at first-line ART failure were compared with regard to outcome of second line ART. Using the Laplace regression model we analyzed the median, 10th, 20th, 30th and 40th percentile of time to viral failure (VF).

RESULTS

Most patients (n = 495; 57.0%) switched from first-line to second-line ART without VF. Patients switching due to detectable VL with (n = 124; 14.2%) or without drug resistance mutations (DRM) (n = 250; 28.8%) experienced VF to their second line regimen sooner (median time, years: 3.43 (95% CI 2.90-3.96) and 3.20 (95% 2.65-3.75), respectively) compared with those who switched without VF (4.53 years). Furthermore level of VL at first-line ART failure had a significant impact on failure of second-line ART starting after 2.5 years of second-line ART.

CONCLUSIONS

In the context of life-long therapy, a median time on second line ART of 4.53 years for these patients is short. To prolong time on second-line ART, further studies are needed on the reasons for therapy changes. Additionally patients with a high VL at first-line VF should be more frequently monitored the period after the therapy switch.

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.

Profile of cabotegravir and its potential in the treatment and prevention of HIV-1 infection: evidence to date

Modern antiretroviral therapy has demonstrated effectiveness in preexposure prophylaxis (PrEP) and treatment of HIV infection. There is a demand for prevention and treatment regimens that could overcome challenges of improving adherence, toxicity, and dosing convenience. Cabotegravir is an integrase strand transfer inhibitor and an analog of dolutegravir. Unlike dolutegravir, cabotegravir has a long half-life and can be formulated into a long-acting nanosuspension for parenteral administration. Initial pharmokinetic studies in humans have demonstrated adequate drug levels with intramuscular (IM) administration at 4 weekly and 8 weekly intervals, with few interactions with commonly used concomitant medications. Preliminary animal PrEP studies have shown that IM cabotegravir can prevent simian/HIV acquisition from rectal, vaginal, and intravenous challenge. Currently, there are two ongoing Phase II studies assessing cabotegravir as a PrEP agent in humans: ÉCLAIR and HPTN077. Cabotegravir has been studied in combination with rilpivirine as long-acting IM maintenance therapy. The Long-Acting Antiretroviral Treatment Enabling study demonstrated that those switching to oral cabotegravir/rilpivirine once virologically suppressed were more likely to maintain suppression than those continuing standard efavirenz-based therapy (82% vs 71% at 24 weeks). Initial results of the Long-Acting Antiretroviral Treatment Enabling-2 study of parenteral regimens found that 12 weeks after randomization to parenteral or oral regimens, there was no difference in proportions virologically suppressed on cabotegravir/rilpivirine daily orally vs IM every 4 weeks or 8 weeks (91% vs 94% vs 95%). The injections were well tolerated as, although they caused injection site pain in most recipients, most participants reported satisfaction with parenteral therapy. Cabotegravir offers a new member of the integrase strand transfer inhibitor class with potential for alternative mode of delivery. We await Phase III studies to define its efficacy and real-world experience to learn which patient groups stand to benefit most from the novel mode of delivery of treatment and PrEP.

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.

Therapy-Emergent Drug Resistance to Integrase Strand Transfer Inhibitors in HIV-1 Patients: A Subgroup Meta-Analysis of Clinical Trials

BACKGROUND

Integrase strand transfer inhibitors (INSTIs) are a novel class of anti-HIV agents that show high activity in inhibiting HIV-1 replication. Currently, licensed INSTIs include raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG); these drugs have played a critical role in AIDS therapy, serving as additional weapons in the arsenal for treating patients infected with HIV-1. To date, long-term data regarding clinical experience with INSTI use and the emergence of resistance remain scarce. However, the literature is likely now sufficiently comprehensive to warrant a meta-analysis of resistance to INSTIs.

METHODS

Our team implemented a manuscript retrieval protocol using Medical Subject Headings (MeSH) via the Web of Science, MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases. We screened the literature based on inclusion and exclusion criteria and then performed a quality analysis and evaluation using RevMan software, Stata software, and the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). We also performed a subgroup analysis. Finally, we calculated resistance rates and risk ratios (RRs) for the three types of drugs.

RESULTS

We identified 26 references via the database search. A meta-analysis of the RAL data revealed that the resistance rate was 3.9% (95% CI = 2.9%-4.9%) for the selected randomized controlled trials (RCTs). However, the RAL resistance rate reached 40.9% (95% CI = 8.8%-72.9%) for the selected observational studies (OBSs). The rates of resistance to RAL that were associated with HIV subtypes A, B, and C as well as with more complex subtypes were 0.1% (95% CI = -0.7%-0.9%), 2.5% (95% CI = 0.5%-4.5%), 4.6% (95% CI = 2.7%-6.6%) and 2.2% (95% CI = 0.7%-3.7%), respectively. The rates of resistance to EVG and DTG were 1.2% (95% CI = 0.2%-2.2%) and 0.1% (95% CI = -0.2%-0.5%), respectively. Furthermore, we found that the RRs for antiviral resistance were 0.414 (95% CI = 0.210-0.816) between DTG and RAL and 0.499 (95% CI = 0.255-0.977) between EVG and RAL. When RAL was separately co-administered with nuclear nucleoside reverse transcriptase inhibitors (NRTIs) or protease inhibitors (PIs), the rates of resistance to RAL were 0.2% (95% CI = -0.1%-0.5%) and 0.2% (95% CI = -0.2%-0.6%), respectively. The ten major integrase mutations (including N155H, Y143C/R, Q148H/R, Y143Y/H, L74L/M, E92Q, E138E/A, Y143C, Q148Q and Y143S) can reduce the sensitivity of RAL and EVG. The resistance of DTG is mainly shown in 13 integrase mutations (including T97T/A, E138E/D, V151V/I, N155H, Q148, Y143C/H/R, T66A and E92Q).

CONCLUSIONS

Our results reveal that the DTG resistance rate was lower than the RAL resistance rate in a head-to-head comparison. Moreover, we confirmed that the EVG resistance rate was lower than the RAL resistance rate. In addition, our results revealed that the resistance rate of RAL was lower than that of efavirenz. The rates of resistance to RAL, EVG and DTG were specifically 3.9%, 1.2% and 0.1%, respectively. Compared with other types of antiviral drugs, the rates of resistance to INSTIs are generally lower. Unfortunately, the EVG and DTG resistance rates could not be compared because of a lack of data.

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.

Clinical challenges in HIV/AIDS: Hints for advancing prevention and patient management strategies

Acquired immune deficiency syndrome has been one of the most devastating epidemics of the last century. The current estimate for people living with the HIV is 36.9 million. Today, despite availability of potent and safe drugs for effective treatment, lifelong therapy is required for preventing HIV re-emergence from a pool of latently infected cells. However, recent evidence show the importance to expand HIV testing, to offer antiretroviral treatment to all infected individuals, and to ensure retention through all the cascade of care. In addition, circumcision, pre-exposure prophylaxis, and other biomedical tools are now available for included in a comprehensive preventive package. Use of all the available tools might allow cutting the HIV transmission in 2030. In this article, we review the status of the epidemic, the latest advances in prevention and treatment, the concept of treatment as prevention and the challenges and opportunities for the HIV cure agenda.

P-glycoprotein (ABCB1) activity decreases raltegravir disposition in primary CD4+P-gphigh cells and correlates with HIV-1 viral load

Objectives

To evaluate the role of P-glycoprotein (P-gp) and multidrug-resistant-protein 1 (MRP1) on raltegravir intracellular drug disposition in CD4+ T cells, investigate the effect of HIV-1 infection on P-gp expression and correlate HIV-1 viraemia with P-gp activity in primary CD4+ T cell subsets.

Methods

The cellular accumulation ratio of [³H]raltegravir was quantified in CD4+ T cell lines overexpressing either P-gp (CEM-P-gp) or MRP1 (CEM-MRP1) and in primary CD3+CD4+ T cells with high (P-gp^high) and low P-gp activity (P-gp^low); inhibition of efflux transporters was confirmed by the intracellular retention of calcein-AM. The correlation of P-gp activity with HIV-1 viraemia was assessed in naive and memory T cell subsets from 21 HIV-1-infected treatment-naive subjects.

Results

[³H]Raltegravir cellular accumulation ratio decreased in CEM-P-gp cells (P < 0.0001). XR9051 (a P-gp inhibitor) and HIV-1 PIs reversed this phenomenon. Primary CD4+P-gp^high cells accumulated less raltegravir (38.4% ± 9.6%) than P-gp^low cells, whereas XR9051 also reversed this effect. In vitro HIV-1 infection of PBMCs and stimulation of CD4+ T cells increased P-gp mRNA and P-gp activity, respectively, while primary CD4+P-gp^high T cells sustained a higher HIV-1 replication than P-gp^low cells. A significant correlation between HIV-1 viraemia and P-gp activity was found in different CD4+ T cell subsets, particularly memory CD4+ T cells (r = 0.792, P < 0.0001).

Conclusions

Raltegravir is a substrate of P-gp in CD4+ T cells. Primary CD4+P-gp^high T cells eliminate intracellular raltegravir more readily than P-gp^low cells and HIV-1 viraemia correlates with P-gp overall activity. Specific CD4+P-gp^high T cell subsets could facilitate the persistence of viral replication in vivo and ultimately promote the appearance of drug resistance.

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.

Single-Tablet Regimens in the Treatment of HIV-1 Infection

The emergence of highly active antiretroviral therapies has decreased mortality, increased viral suppression, and significantly reduced the risk of the sexual transmission of HIV.

Virological failure in patients with HIV-1 subtype C receiving antiretroviral therapy: an analysis of a prospective national cohort in Sweden

BACKGROUND

People with HIV-1 in low-income and middle-income countries increasingly need second-line regimens with boosted protease inhibitors. However, data are scarce for treatment response in patients with HIV-1 subtype C (HIV-1C), which is predominant in these regions. We aimed to examine factors associated with virological failure in patients in a standardised national health-care setting.

METHODS

We analysed data for participants in InfCare HIV, a prospective national cohort that includes more than 99% of people with HIV in Sweden. We extracted data for the cohort from the InfCare HIV database on Jan 14, 2015. Baseline was initiation of antiretroviral therapy. We used logistic regression to assess factors associated with primary virological failure (failure to suppress HIV-1 within 9 months) in patients with HIV-1B and HIV-1C and calculated odds ratios (OR) for failure. We also used Cox regression models to calculate hazard ratios (HR) for time-to-secondary virological failure (detectable viral load after initial virological suppression). We did homology-based molecular modelling to assess docking.

FINDINGS

We included 1077 patients with HIV-1B and 596 with HIV-1C. In multivariate regression analysis, pre-therapy higher viral load (OR 1·82, 95% CI 1·49-2·21; p<0·0001), subtype C infection (1·75, 1·06-2·88; p=0·028), and boosted protease inhibitor-based regimens (1·55, 1·45-2·11; p=0·004) were associated with increased risk of primary virological failure. Individuals with HIV-1C who were given therapy with boosted protease inhibitors had earlier time-to-secondary virological failure than did those with HIV-1B given similar regimens (adjusted HR 1·92, 95% CI 1·30-2·83; p=0·002). Molecular modelling suggested lower affinity for protease inhibitors to HIV-1C protease than to HIV-1B.

INTERPRETATION

Our findings suggest an increased risk of virological failure in patients with HIV-1C, especially in those on boosted protease inhibitor-based regimens. Future studies should further dissect the biochemical and viral mechanisms of resistance to protease inhibitors in patients with non-B subtypes of HIV-1, including clinical studies to assess the efficacy of boosted protease inhibitor-based regimens in low-income and middle income countries.

FUNDING

Karolinska Institutet Research Foundation, Swedish Research Council, Stockholm County Council, Swedish Physicians against AIDS, US National Institutes of Health, University of Missouri.

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%.