Failure of combined antiretroviral therapy intensification with maraviroc and raltegravir in chronically HIV-1 infected patients to reduce the viral reservoir: the IntensHIV randomized trial

The efficacy and tolerability of latency-reversing agents in reactivating the HIV-1 reservoir in clinical studies: a systematic review

Introduction

Understanding the clinical potency of latency-reversing agents (LRAs) on the HIV-1 reservoir is useful to deploy future strategies. This systematic review evaluated the effects of LRAs in human intervention studies.

Methods

A literature search was performed using medical databases focusing on studies with adults living with HIV-1 receiving LRAs. Eligibility criteria required participants from prospective clinical studies, a studied compound hypothesised as LRA, and reactivation or tolerability assessments. Relevant demographical data, LRA reactivation capacity, reservoir size, and adverse events were extracted. A study quality assessment with analysis of bias was performed by RoB 2 and ROBINS-I tools. The primary endpoints were HIV-1 reservoir reactivation after LRA treatment quantified by cell-associated unspliced HIV-1 RNA, and LRA tolerability defined by adverse events. Secondary outcomes were reservoir size and the effect of LRAs on analytical treatment interruption (ATI) duration.

Results

After excluding duplicates, 5182 publications were screened. In total 45 publications fulfilled eligibility criteria including 26 intervention studies and 16 randomised trials. The risk of bias was evaluated as high. Chromatin modulators were the main investigated LRA class in 24 studies. Participants were mostly males (90.1%). Where reported, HIV-1 subtype B was most frequently observed. Reactivation after LRA treatment occurred in 78% of studies and was observed with nearly all chromatin modulators. When measured, reactivation mostly occurred within 24 h after treatment initiation. Combination LRA strategies have been infrequently studied and were without synergistic reactivation. Adverse events, where reported, were mostly low grade, yet occurred frequently. Seven studies had individuals who discontinued LRAs for related adverse events. The reservoir size was assessed by HIV-1 DNA in 80% of studies. A small decrease in reservoir was observed in three studies on immune checkpoint inhibitors and the histone deacetylase inhibitors romidepsin and chidamide. No clear effect of LRAs on ATI duration was observed.

Conclusion

This systematic review provides a summary of the reactivation of LRAs used in current clinical trials whilst highlighting the importance of pharmacovigilance. Highly heterogeneous study designs and underrepresentation of relevant patient groups are to be considered when interpreting these results. The observed reactivation did not lead to cure or a significant reduction in the size of the reservoir. Finding more effective LRAs by including well-designed studies are needed to define the required reactivation level to reduce the HIV-1 reservoir.

Inflammasomes as mediators of inflammation in HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) infection is a chronic disease without a known cure. The advent of effective antiretroviral therapy (ART) has enabled people with HIV (PWH) to have significantly prolonged life expectancies. As a result, morbidity and mortality associated with HIV-1 infection have declined considerably. However, these individuals experience chronic systemic inflammation whose multifaceted etiology is associated with other numerous comorbidities. Inflammasomes are vital mediators that contribute to inflammatory signaling in HIV-1 infection. Here, we provide an overview of the inflammatory pathway that underlies HIV-1 infection, explicitly highlighting the role of the NLRP3 inflammasome. We also delineate the current literature on inflammasomes and the therapeutic targeting strategies aimed at the NLRP3 inflammasome to moderate HIV-1 infection-associated inflammation. Here we describe the NLRP3 inflammasome as a key pathway in developing novel therapeutic targets to block HIV-1 replication and HIV-1-associated inflammatory signaling. Controlling the inflammatory pathways is critical in alleviating the morbidities and mortality associated with chronic HIV-1 infection in PWH.

Why the HIV Reservoir Never Runs Dry: Clonal Expansion and the Characteristics of HIV-Infected Cells Challenge Strategies to Cure and Control HIV Infection

Antiretroviral therapy (ART) effectively reduces cycles of viral replication but does not target proviral populations in cells that persist for prolonged periods and that can undergo clonal expansion. Consequently, chronic human immunodeficiency virus (HIV) infection is sustained during ART by a reservoir of long-lived latently infected cells and their progeny. This proviral landscape undergoes change over time on ART. One of the forces driving change in the landscape is the clonal expansion of infected CD4 T cells, which presents a key obstacle to HIV eradication. Potential mechanisms of clonal expansion include general immune activation, antigenic stimulation, homeostatic proliferation, and provirus-driven clonal expansion, each of which likely contributes in varying, and largely unmeasured, amounts to maintaining the reservoir. The role of clinical events, such as infections or neoplasms, in driving these mechanisms remains uncertain, but characterizing these forces may shed light on approaches to effectively eradicate HIV. A limited number of individuals have been cured of HIV infection in the setting of bone marrow transplant; information from these and other studies may identify the means to eradicate or control the virus without ART. In this review, we describe the mechanisms of HIV-1 persistence and clonal expansion, along with the attempts to modify these factors as part of reservoir reduction and cure strategies.

Microglia: The Real Foe in HIV-1-Associated Neurocognitive Disorders?

The current use of combined antiretroviral therapy (cART) is leading to a significant decrease in deaths and comorbidities associated with human immunodeficiency virus type 1 (HIV-1) infection. Nonetheless, none of these therapies can extinguish the virus from the long-lived cellular reservoir, including microglia, thereby representing an important obstacle to curing HIV. Microglia are the foremost cells infected by HIV-1 in the central nervous system (CNS) and are believed to be involved in the development of HIV-1-associated neurocognitive disorder (HAND). At present, the pathological mechanisms contributing to HAND remain unclear, but evidence suggests that removing these infected cells from the brain, as well as obtaining a better understanding of the specific molecular mechanisms of HIV-1 latency in these cells, should help in the design of new strategies to prevent HAND and achieve a cure for these diseases. The goal of this review was to study the current state of knowledge of the neuropathology and research models of HAND containing virus susceptible target cells (microglial cells) and potential pharmacological treatment approaches under investigation.

Prolonged administration of maraviroc reactivates latent HIV in vivo but it does not prevent antiretroviral-free viral rebound

Human immunodeficiency virus (HIV) remains incurable due to latent viral reservoirs established in non-activated CD4 T cells that cannot be eliminated via antiretroviral therapy. Current efforts to cure HIV are focused on identifying drugs that will induce viral gene expression in latently infected cells, commonly known as latency reversing agents (LRAs). Some drugs have been shown to reactivate latent HIV but do not cause a reduction in reservoir size. Therefore, finding new LRAs or new combinations or increasing the round of stimulations is needed to cure HIV. However, the effects of these drugs on viral rebound after prolonged treatment have not been evaluated. In a previous clinical trial, antiretroviral therapy intensification with maraviroc for 48 weeks caused an increase in residual viremia and episomal two LTR-DNA circles suggesting that maraviroc could reactivate latent HIV. We amended the initial clinical trial to explore additional virologic parameters in stored samples and to evaluate the time to viral rebound during analytical treatment interruption in three patients. Maraviroc induced an increase in cell-associated HIV RNA during the administration of the drug. However, there was a rapid rebound of viremia after antiretroviral therapy discontinuation. HIV-specific T cell response was slightly enhanced. These results show that maraviroc can reactivate latent HIV in vivo but further studies are required to efficiently reduce the reservoir size.

Maraviroc reactivates HIV with potency similar to that of other latency reversing drugs without inducing toxicity in CD8 T cells

Human immunodeficiency virus (HIV) remains incurable due to latent reservoirs established in non-activated CD4 T cells. Current efforts to achieve a functional cure rely on immunomodulatory strategies focused on enhancing the functions of cytotoxic cells. Implementation of these actions requires a coordinated activation of the viral transcription in latently infected cells so that the reservoir became visible and accessible to cytotoxic cells. As no latency reversing agent (LRA) has been shown to be completely effective, new combinations are of increasing importance. Recent data have shown that maraviroc is a new LRA. In this work, we have explored how the combination of maraviroc with other LRAs influences on HIV reactivation using in vitro latency models as well as on the cell viability of CD8 T cells from ART-treated patients. Maraviroc reactivated HIV with a potency similar to other LRAs. Triple combinations resulted toxic and were rejected. No dual combination was synergistic. The combination with panobinostat or disulfiram maintained the effect of both drugs without inducing cell proliferation or toxicity. Maraviroc does not alter the viability of CD8 T cells isolated from patients under antiretroviral treatment. This finding enhances the properties of maraviroc as a LRA.

Do Combination Antiretroviral Therapy Regimens for HIV Infection Feature Diverse T-Cell Phenotypes and Inflammatory Profiles?

Immune abnormalities featuring HIV infection persist despite the use of effective combination antiretroviral therapy (cART) and may be linked to the development of noninfectious comorbidities. The aim of the present narrative, nonsystematic literature review is to understand whether cART regimens account for qualitative differences in immune reconstitution. Many studies have reported differences in T-cell homeostasis, inflammation, coagulation, and microbial translocation parameters across cART classes and in the course of triple vs dual regimens, yet such evidence is conflicting and not consistent. Possible reasons for discrepant results in the literature are the paucity of randomized controlled clinical trials, the relatively short follow-up of observational studies, the lack of clinical validation of the numerous inflammatory biomarkers utilized, and the absence of research on the effects of cART in tissues. We are currently thus unable to establish if cART classes and regimens are truly accountable for the differences observed in immune/inflammation parameters in different clinical settings. Questions still remain as to whether an early introduction of cART, specifically in the acute stage of disease, or newer drugs and novel dual drug regimens are able to significantly impact the quality of immune reconstitution and the risk of disease progression in HIV-infected subjects.

Positive feedback through inflammation creates bistable behavior in HIV tissue sanctuaries

Combination Antiretroviral Therapy (cART) consists of a cocktail of drugs administered to HIV-infected patients that can suppress the amount of HIV in the patient's blood plasma to an undetectable level. Our previous work has suggested that some HIV-infected patients, despite being placed on cART, can still have ongoing viral replication occurring in self-sustaining inflamed lymph node follicle sanctuary sites. Spatial models of the putative sites show that inflammation is a necessary condition for ongoing HIV replication. In this study, we model the hypothesis that ongoing HIV replication may provide a sufficiently strong pro-inflammatory signal to maintain inflammation levels consistent with continued HIV replication. A system of ordinary differential equations integrated with a reactive-diffusion system is used to model the HIV dynamics and the diameter of a lymph node follicle as a function of time and external influence. The estimates of the parameters in our model come from prior data when available. The results of our study show that these dynamics have two stable steady-state solutions, one with low inflammation and no ongoing HIV replication in the site, and one with high inflammation and high levels of ongoing HIV replication in the site. We furthermore show that the system can transition between the two outcomes in response to a transient exogenous addition of pro-inflammatory signaling, consistent with the antigenic stimulus of a secondary infection. The spatial isolation of the sites results in a low viral load in the blood plasma for both conditions.

Barriers and strategies to achieve a cure for HIV

9 years since the report of a cure for HIV after C-C chemokine receptor type 5 Δ32 stem cell transplantation, no other case of HIV cure has been reported, despite much research. However, substantial progress has been made in understanding the biology of the latent HIV reservoir, and in measuring the amount of virus that persists after antiretroviral therapy (ART) with increasingly sophisticated approaches. This knowledge is being translated into a long pipeline of clinical trials seeking to reduce viral persistence in participants on suppressive treatment and ultimately to allow safe cessation of ART. In this Review, we discuss the main barriers preventing the development of an HIV cure, methods used to measure HIV persistence in individuals on ART, clinical strategies that aim to cure HIV, and future directions for studies in the field of HIV cure research.

Re-boost immunizations with the peptide-based therapeutic HIV vaccine, Vacc-4x, restores geometric mean viral load set-point during treatment interruption

Background

Vacc-4x, a therapeutic HIV vaccine candidate has previously induced a significant reduction in viral load (VL) set-point compared to placebo upon interruption of combination anti-retroviral therapy (ART) (2007/1 study). This study, (2012/1), explored the potential to maintain Vacc-4x effect by re-boosting eligible 2007/1 study participants.

Methods

Participant inclusion required 2007/1 participants to have completed all Vacc-4x immunizations and interrupted ART for up to 26 weeks. At weeks (wk)0 and 2, participants received intradermal (i.d.) Vacc-4x booster immunizations (1.2mg) on ART with GM-CSF (60μg) i.d. as a local adjuvant. ART was interrupted for up to 16 weeks (wk12-wk28). Participants were then followed on ART until wk36. VL set-point, total proviral DNA (pvDNA) and immunogenicity assessed by IFN-γ ELISPOT, T-cell proliferation and delayed type hypersensitivity (DTH) reactions were compared to participants’ values in the 2007/1 study where available.

Results

This open, multicenter, clinical study enrolled 33 participants from 9 clinical trial sites in the US and Europe. In the per-protocol (PP) population, the VL set-point geometric mean (GM) 18162 copies/mL was not significantly changed compared to the 2007/1 study (GM VL 22035 copies/mL), (p = 0.453, n = 18). For participants with available preART VL values, the VL set-point (GM 26279 copies/mL) remained significantly lower than the preART VL set-point (GM 74048 copies/mL, p = 0.021, n = 13). A statistically significant reduction in pvDNA (49%) from baseline to wk4 was observed (p = 0.03, n = 26). DTH responses (wk4) increased significantly from baseline (p = 0.006, n = 30) and compared to the 2007/1 study (p = 0.022, n = 29) whilst the proportion of participants with ELISPOT and T-cell proliferation responses was similar between the two studies.

Conclusions

Vacc-4x booster immunizations safely maintained the mean VL set-point at that established following primary Vacc-4x therapeutic immunization. The reduction in pvDNA during ART supports the potential for Vacc-4x immunization to reduce HIV reservoirs and thereby contribute to combination HIV cure strategies.

HIV 2-LTR experiment design optimization

Clinical trials are necessary in order to develop treatments for diseases; however, they can often be costly, time consuming, and demanding to the patients. This paper summarizes several common methods used for optimal design that can be used to address these issues. In addition, we introduce a novel method for optimizing experiment designs applied to HIV 2-LTR clinical trials. Our method employs Bayesian techniques to optimize the experiment outcome by maximizing the Expected Kullback-Leibler Divergence (EKLD) between the a priori knowledge of system parameters before the experiment and the a posteriori knowledge of the system parameters after the experiment. We show that our method is robust and performs equally well if not better than traditional optimal experiment design techniques.

Peering into the HIV reservoir

The main obstacle to HIV eradication is the establishment of a long-term persistent HIV reservoir. Although several therapeutic approaches have been developed to reduce and eventually eliminate the HIV reservoir, only a few have achieved promising results. A better knowledge of the mechanisms involved in the establishment and maintenance of HIV reservoir is of utmost relevance for the design of new therapeutic strategies aimed at purging it with the ultimate goal of achieving HIV eradication or alternatively a functional cure. In this regard, it is also important to take a close look into the cellular HIV reservoirs other than resting memory CD4 T-cells with key roles in reservoir maintenance that have been recently described. Unraveling the special characteristics of these HIV cellular compartments could aid us in designing new therapeutic strategies to deplete the latent HIV reservoir.

Peripheral blood HIV-1 DNA dynamics in antiretroviral-treated HIV/HCV co-infected patients receiving directly-acting antivirals

BACKGROUND

Aim was to determine the dynamics of peripheral blood mononuclear cells (PBMC)- associated total HIV-1 DNA in successfully ART-treated HIV/HCV co-infected patients receiving DAA treatment and to explore possible virological hypotheses underlying the phenomenon.

METHODS

Longitudinal, single-centre study measuring total HIV-1 DNA before the start of DAA, at the end of treatment (EOT), and 3 months after treatment. Univariable and multivariable analyses were used to assess factors associated with HIV-1 DNA increase ≥0.5 Log copies/million PBMC. Episomal 2-LTR forms, residual HIV-1 viremia and proviral DNA quasispecies evolution were also investigated.

RESULTS

119 successfully ART-treated HIV/HCV co-infected patients were included. Median baseline HIV-1 DNA was 3.84 Log copies/million PBMC (95%CI 3.49-4.05), and no significant variation with respect to baseline was found at EOT and after 3 months of DAA termination. In 17% of cases an increase ≥0.5 Log copies/million PBMC was observed at EOT compared to baseline. HIV-1 DNA increase was independently associated with lower baseline HIV-1 DNA, longer HIV suppression, raltegravir-based ART and previous exposure to interferon/ribavirin for HCV treatment. In none of the patients with HIV-1 DNA increase, 2-LTR forms were detected at baseline, while in 2 cases 2-LTR forms were found at EOT, without association with residual HIV-1 RNA viremia. No evidence of viral evolution was observed.

CONCLUSIONS

In successfully ART-treated HIV/HCV co-infected patients receiving DAA, PBMC-associated total HIV-1 DNA was quite stable over time, but some patients showed a considerable increase at EOT when compared to baseline. A significantly higher risk of HIV DNA increase was found, in presence of lower cellular HIV reservoir at baseline. Activation of replicative-competent virus generating new rounds of viral replication seems unlikely, while mobilization of cell-associated HIV from tissue reservoirs could be hypothesized.

Strategies to target non-T-cell HIV reservoirs

PURPOSE OF REVIEW

A central question for the HIV cure field is to determine new ways to target clinically relevant, latently and actively replicating HIV-infected cells beyond resting memory CD4 T cells, particularly in anatomical areas of low drug penetrability.

RECENT FINDINGS

HIV eradication strategies being positioned for targeting HIV for extinction in the CD4 T-cell compartment may also show promise in non-CD4 T-cells reservoirs. Furthermore, several exciting novel therapeutic approaches specifically focused on HIV clearance from non-CD4 T-cell populations are being developed.

SUMMARY

Although reservoir validity in these non-CD4 T cells continues to remain debated, this review will highlight recent advances and make an argument as to their clinical relevancy as we progress towards an HIV cure.

The CCR5-antagonist Maraviroc reverses HIV-1 latency in vitro alone or in combination with the PKC-agonist Bryostatin-1

A potential strategy to cure HIV-1 infection is to use latency reversing agents (LRAs) to eliminate latent reservoirs established in resting CD4+ T (rCD4+) cells. As no drug has been shown to be completely effective, finding new drugs and combinations are of increasing importance. We studied the effect of Maraviroc (MVC), a CCR5 antagonist that activates NF-κB, on HIV-1 replication from latency. HIV-1-latency models based on CCL19 or IL7 treatment, before HIV-1 infection were used. Latently infected primary rCD4+ or central memory T cells were stimulated with MVC alone or in combination with Bryostatin-1, a PKC agonist known to reverse HIV-1 latency. MVC 5 μM and 0.31 μM were chosen for further studies although other concentrations of MVC also increased HIV-1 replication. MVC was as efficient as Bryostatin-1 in reactivating X4 and R5-tropic HIV-1. However, the combination of MVC and Bryostatin-1 was antagonistic, probably because Bryostatin-1 reduced CCR5 expression levels. Although HIV-1 reactivation had the same tendency in both latency models, statistical significance was only achieved in IL7-treated cells. These data suggest that MVC should be regarded as a new LRA with potency similar as Bryostatin-1. Further studies are required to describe the synergistic effect of MVC with other LRAs.

A Drug-Free Zone--Lymph Nodes as a Safe Haven for HIV

Understanding where and how the HIV latent reservoir persists is essential for developing rational HIV cure strategies. In a recent paper in Nature, Lorenzo-Redondo et al. (2016) demonstrate that HIV persists and actively evolves within lymph nodes due to low antiretroviral drug penetration, revealing the need to target these drug-privileged sites.

Comorbidities associated with HIV and antiretroviral therapy (clinical sciences): a workshop report

In the era of combination antiretroviral therapy (ART), parsing out the effects of HIV vs ART on health outcomes is challenging. Nadir CD4 count, a marker of the extent of immunosuppression, has significant long-term impact on an array of disease states in HIV+ persons; however, in the dental literature, reporting of pre-ART exposure to immunosuppression has largely been ignored and this limits the validity of previous studies. In Workshop A1, we explain fully the importance of nadir CD4, pre-ART immunosuppression, and identify a need to include specific variables in future research. The questions posed herein are challenging, typically not neatly addressed by any one study and require integration of the latest evidence from the wider medical literature. We consider topics beyond the confines of the oral cavity and examine oral health in the complex context of ART era HIV immunopathophysiology. We depict how variability in geographic setting and time period (pre- and post-ART era) can impact oral conditions - influencing when HIV infection was detected (at what CD4 count), the type and timing of ART as well as social determinants such as strong stigma and limited access to care. We hope our Workshop will stir debate and energize a rigorous focus on relevant areas of future research in HIV/AIDS.

HIV Replication at Low Copy Number and its Correlation with the HIV Reservoir: A Clinical Perspective

The efficacy of combination therapy (antiretroviral therapy - ARV) is demonstrated by the high rates of viral suppression achieved in most treated HIV patients. Whereas contemporary treatments may continuously suppress HIV replication, they do not eliminate the latent reservoir, which can reactivate HIV infection if ARV is discontinued. The persistence of HIV proviral DNA and infectious viruses in CD4+ T cells and others cells has long been considered a major obstacle in eradicating the HIV virus in treated patients. Moreover, recent studies have demonstrated the persistence of HIV replication at low copies in most patients on suppressive ARV. The source of this ‘residual viraemia’ and whether it declines over years of therapy remain unknown. Similarly, little is known regarding the biological relationships between the HIV reservoir and viral replication at low copies. The question of whether this ‘residual viraemia’ represents active replication or the release of non-productive virus from the reservoir has not been adequately resolved.

From a clinical perspective, both the quantification of the HIV reservoir and the detection of low levels of replication in full-responder patients on prolonged ARV may provide important information regarding the effectiveness of treatment and the eradication of HIV. To date, the monitoring of these two parameters has been conducted only for research purposes; the routine use of standardised tests procedure is lacking. This review aims to assess the current data regarding the correlation between HIV replication at low copies and the HIV reservoir and to provide useful information for clinicians.

Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial

Whether initiation of antiretroviral therapy (ART) regimens aimed at achieving greater concentrations within gut associated lymphoid tissue (GALT) impacts the level of mucosal immune reconstitution, inflammatory markers and the viral reservoir remains unknown. We included 12 HIV- controls and 32 ART-naïve HIV patients who were randomized to efavirenz, maraviroc or maraviroc+raltegravir, each with fixed-dose tenofovir disoproxil fumarate/emtricitabine. Rectal and duodenal biopsies were obtained at baseline and at 9 months of ART. We performed a comprehensive assay of T-cell subsets by flow cytometry, T-cell density in intestinal biopsies, plasma and tissue concentrations of antiretroviral drugs by high-performance liquid chromatography/mass spectroscopy, and plasma interleukin-6 (IL-6), lipoteichoic acid (LTA), soluble CD14 (sCD14) and zonulin-1 each measured by ELISA. Total cell-associated HIV DNA was measured in PBMC and rectal and duodenal mononuclear cells. Twenty-six HIV-infected patients completed the follow-up. In the duodenum, the quadruple regimen resulted in greater CD8+ T-cell density decline, greater normalization of mucosal CCR5+CD4+ T-cells and increase of the naïve/memory CD8+ T-cell ratio, and a greater decline of sCD14 levels and duodenal HIV DNA levels (P = 0.004 and P = 0.067, respectively), with no changes in HIV RNA in plasma or tissue. Maraviroc showed the highest drug distribution to the gut tissue, and duodenal concentrations correlated well with other T-cell markers in duodenum, i.e., the CD4/CD8 ratio, %CD4+ and %CD8+ HLA-DR+CD38+ T-cells. Maraviroc use elicited greater activation of the mucosal naïve CD8+ T-cell subset, ameliorated the distribution of the CD8+ T-cell maturational subsets and induced higher improvement of zonulin-1 levels. These data suggest that combined CCR5 and integrase inhibitor based combination therapy in ART treatment naïve patients might more effectively reconstitute duodenal immunity, decrease inflammatory markers and impact on HIV persistence by cell-dependent mechanisms, and show unique effects of MVC in duodenal immunity driven by higher drug tissue penetration and possibly by class-dependent effects.

Discordant responses to cART in HIV-1 patients in the era of high potency antiretroviral drugs: clinical evaluation, classification, management prospects

The goal of antiretroviral treatment (ART) in HIV-1 patients is immune reconstitution following control of viral replication. CD4+ cell number/proportions are a crude but essential correlate of immune reconstitution. Despite suppression of HIV replication, a fraction of ART-treated patients still fails to fully reconstitute CD4+ T cell numbers (immunological nonresponders, INRs). New drugs, regimens and treatment strategies led to increased efficacy, lower side effects and higher virological success rates in clinical practice. The multitude of described immune defects and clinical events accompanying INR opposed to the marginal effect of antiretroviral intensification or immunotherapy trials underline the need for continuing efforts at understanding the mechanisms that underlie INR. Here, we reassess INR definition, frequency, and the achievements of active clinical and translational research suggesting a shared definition for insufficient, partial and complete CD4+ cell number recovery thus improving homogeneity in patient selection and mechanism identification.

Virologic and immunologic effects of adding maraviroc to suppressive antiretroviral therapy in individuals with suboptimal CD4+ T-cell recovery

BACKGROUND

Combination antiretroviral therapy (ART) suppresses HIV-1 replication, but does not restore CD4 T-cell counts in all individuals. To investigate the effects of maraviroc on HIV-1 persistence and the relations between virologic and immunologic parameters in individuals with incomplete CD4 T-cell recovery, we performed a prospective, open-label pilot trial in which maraviroc was added to a suppressive ART regimen for 24 weeks.

DESIGN

A5256 was a single-arm trial in which individuals on suppressive ART with incomplete CD4 T-cell recovery added maraviroc for 24 weeks.

METHODS

We quantified low-level, residual viremia in plasma and total HIV-1 DNA and 2-long terminal repeat (2-LTR) circles in peripheral blood mononuclear cells before and after maraviroc intensification. We also evaluated markers of CD4 and CD8 T-cell immune activation (%CD38HLA-DR) and apoptosis (%caspase3/Bcl-2).

RESULTS

No effect of maraviroc was found on the probability of detectable plasma viremia (≥1 copy/ml; n = 31, exact McNemar P = 1.0) or detectable 2-LTR circles (n = 28, P = 0.25) or on total HIV-1 DNA (n = 28, 90% confidence interval -0.1, +0.3 log10 copies/10 CD4 T-cells). Premaraviroc HIV-1 DNA levels were inversely related to premaraviroc %CD38HLA-DR CD4 T-cells (Spearman = -0.52, P = 0.004), and lower premaraviroc HIV-1 DNA levels were associated with larger decreases in %CD38HLA-DR CD4 T-cells during maraviroc intensification (Spearman = 0.44, P = 0.018).

CONCLUSION

In individuals on suppressive ART with incomplete CD4 T-cell recovery, maraviroc intensification did not affect measures of HIV-1 persistence but did decrease persistent CD4 T-cell immune activation especially in individuals with low preintensification levels of HIV-1 DNA.

Intensifying Antiretroviral Therapy With Raltegravir and Maraviroc During Early Human Immunodeficiency Virus (HIV) Infection Does Not Accelerate HIV Reservoir Reduction

Background. Persistent human immunodeficiency virus (HIV) within the CD4⁺ T-cell reservoir is an obstacle to eradication. We hypothesized that adding raltegravir and maraviroc to standard combination antiretroviral therapy (cART) during early HIV infection could substantially reduce viral reservoirs as a step towards eradication.

Methods. A prospective, randomized, double-blinded, placebo-controlled pilot trial enrolled 32 participants with documented early (<6 months) HIV infection to either standard cART (emtricitabine/tenofovir/lopinavir/ritonavir) or intensive cART (standard regimen + raltegravir/maraviroc). Human immunodeficiency virus reservoirs were assessed at baseline and at 48 weeks by (1) proviral DNA, (2) cell-associated RNA, and (3) replication-competent virus, all from purified blood CD4⁺ T cells, and (4) gut proviral DNA. A multiassay algorithm (MAA) on baseline sera estimated timing of infection.

Results. Thirty individuals completed the study to the 48-week endpoint. The reduction in blood proviral burden was −1.03 log DNA copies/10⁶ CD4⁺ T cells versus −.84 log in the standard and intensive groups, respectively (P = .056). Overall, there was no significant difference in the rate of decline of HIV-associated RNA, replication-competent virus in blood CD4⁺ T cells, nor proviral gut HIV DNA to 48 weeks. Individuals who presented with more recent HIV infection had significantly lower virus reservoirs, and cART tended to reduce their reservoirs to a greater extent.

Conclusions. Intensive cART led to no additional reduction in the blood virus reservoir at 48 weeks compared with standard cART. Human immunodeficiency virus reservoir size is smaller earlier in HIV infection. Other novel treatment strategies in combination with early cART will be needed to eliminate the HIV latent reservoir.