Clinical trials of antiretroviral treatment interruption in HIV-infected individuals

Mosaic vaccine-induced antibody-dependent cellular phagocytosis associated with delayed HIV-1 viral load rebound post treatment interruption

A heterologous Ad26/MVA vaccine was given prior to an analytic treatment interruption (ATI) in people living with HIV-1 (mainly CRF01_AE) who initiated antiretroviral treatment (ART) during acute HIV-1. We investigate the impact of Ad26/MVA vaccination on antibody (Ab)-mediated immune responses and their effect on time to viral rebound. The vaccine mainly triggers vaccine-matched binding Abs while, upon viral rebound post ATI, infection-specific CRF01_AE binding Abs increase in all participants. Binding Abs are not associated with time to viral rebound. The Ad26/MVA mosaic vaccine profile consists of correlated non-CRF01_AE binding Ab and Fc effector features, with strong Ab-dependent cellular phagocytosis (ADCP) responses. CRF01_AE-specific ADCP responses (measured either prior to or post ATI) are significantly higher in individuals with delayed viral rebound. Our results suggest that vaccines eliciting cross-reactive responses with circulating viruses in a target population could be beneficial and that ADCP responses may play a role in viral control post treatment interruption.

Definition of Virological Endpoints Improving the Design of Human Immunodeficiency Virus (HIV) Cure Strategies Using Analytical Antiretroviral Treatment Interruption

BACKGROUND

Analytical treatment interruption (ATI) is the gold standard in HIV research for assessing the capability of new therapeutic strategies to control viremia without antiretroviral treatment (ART). The viral setpoint is commonly used as endpoint to evaluate their efficacy. However, in line with recommendations from a consensus meeting, to minimize the risk of increased viremia without ART, trials often implement short ATI phases and stringent virological ART restart criteria. This approach can limit the accurate observation of the setpoint.

METHODS

We analyzed viral dynamics in 235 people with HIV from 3 trials, examining virological criteria during ATI phases. Time-related (eg time to rebound, peak, and setpoint) and viral load magnitude-related criteria (peak, setpoint, and time-averaged AUC [nAUC]) were described. Spearman correlations were analyzed to identify (1) surrogate endpoints for setpoint and (2) optimal virological ART restart criteria mitigating the risks of ART interruption and the evaluation of viral control.

RESULTS

Comparison of virological criteria between trials showed strong dependencies on ATI design. Similar correlations were found across trials, with nAUC the most strongly correlated with the setpoint, with correlations >0.70. A threshold >100 000 copies/mL for 2 consecutive measures is requested as a virological ART restart criterion.

CONCLUSIONS

Our results are in line with recommendations and emphasize the benefits of an ATI phase >12 weeks, with regular monitoring, and a virological ART restart criterion of 10 000 copies/mL to limit the risk for patients while capturing enough information to keep nAUC as an optimal proxy to the setpoint.

Vaccinating people living with HIV: a fast track to preventive and therapeutic HIV vaccines

Globally, the number of new HIV infections remains unacceptably high, and urgent new approaches are needed to advance HIV vaccine science. However, the development of a preventive HIV vaccine has proven to be an intractable scientific challenge. Recent advances in HIV immunogen design have taken the field a step closer to triggering the rare precursors of broadly neutralising antibodies, which are widely assumed to be necessary for a vaccine. Nonetheless, these same studies and previous studies in people living with HIV have also highlighted the major hurdles that must be overcome to boost the cross-reactivity and potency of these responses to sufficient levels. Here, we describe an opportunity for fast-tracking the evaluation of candidate preventive and therapeutic vaccines by immunising people with HIV who are antiretroviral therapy suppressed. We argue that such studies, unlike traditional studies of vaccines in participants not infected with HIV, will be faster and more informative and will allow the vaccine field to bypass multiple hurdles. This approach will accelerate the process of defining the capacity of immunogens to trigger relevant antibodies, currently an extremely slow and expensive pathway, and provide a quick path to creating an HIV vaccine.

Three-stage modeling of HIV infection and implications for antiretroviral therapy

We consider a deterministic model of HIV infection that involves macrophages as a long-term active reservoir to describe all three stages of the disease process: the acute stage, chronic infection, and the transition to AIDS. The proposed model is shown to retain crucial properties, such as the positivity of solutions, regardless of variations in model parameters. A dynamical analysis is performed to identify the local stability properties of the viral clearance steady state. This analysis illustrates how chronically infected macrophages can explain the progression to AIDS and provoke viral explosion, while previous models do not. We further demonstrate that the infected T-cell population, even if not responsible for the majority of new infections that lead to viral explosion, may contribute significantly to the transition amongst the three stages of infection. Moreover, we explore the implications of the model for the administration of antiretroviral therapy (ART) and provide quantitative estimates that emphasize the time sensitive nature of treatment initiation and the level of drug efficacy. Finally, we study the effects of treatment interruption on the disease dynamics predicted by the model and elucidate the influence of both interruption time and duration.

Understanding participant perspectives around HIV-1 cure-related studies involving antiretroviral analytical treatment interruptions in the United Kingdom

Background

To test efficacy, HIV cure-related trials often require a period of intensively monitored interruption of antiretroviral therapy (ART) (analytical treatment interruption or ATI). As individuals who started ART during primary HIV-1 infection (PHI) are often recruited, we have asked people already enrolled into an observational PHI study about their willingness and concerns around participating in cure-related studies involving ATIs.

Methods

People who were diagnosed with PHI and started ART, attending two London HIV clinics, provided informed consent to complete a digital survey in clinic between 21/07/21 to October 31, 2023. Questions comprised sociodemographics, motivations, concerns and practical considerations influencing willingness to participate in studies involving ATIs. Hierarchical clustering of responses was performed using the 'pheatmap' R statistical package and ranked from most to least concerned. Responses were cross-referenced with enrolment into an ATI study which recruited from this cohort.

Results

Of 352 eligible participants, 75 completed the survey. The majority were white, cisgender men who have sex with men, 34/75 (45 %) were born outside the UK. 29 (39 %) expressed interest in joining ATI studies. Participants who were interested or unsure in joining ATI studies were primarily motivated (53/65, 82 % very or moderately interested) by an altruistic desire to help scientific research. Across all participants, onward HIV transmission was the predominant concern (67/75, 89 % very or moderately concerned), and similar levels of concerns reported if the HIV-1 viral load threshold to restarting ART was increased from 500 to 50 000 copies/mL. Most participants preferred weekly (23/65, 35 %) or fortnightly (11/65, 17 %) viral load monitoring during an ATI. Before taking part in a study involving an ATI, participants stated they would prefer to discuss this with their HIV doctor (55/65, 85 %).

Conclusion

In this small survey, 39 % of respondents expressed interest in joining studies involving ATIs, primarily for altruistic reasons. Participants were more interested in joining a potential ATI study if a novel intervention was included than simply an ATI alone. The main concern expressed was risk of viral transmission. To inform practical and study design considerations for future ATI studies, unrestricted access for mitigation of transmission risk should be included, and regular, frequent viral load monitoring is preferred.

Development of lipophilic ester prodrugs of dolutegravir for intestinal lymphatic transport

The establishment of latent cellular and anatomical viral reservoirs is a major obstacle to achieving a cure for people infected by HIV. Mesenteric lymph nodes (MLNs) are one of the most important anatomical reservoirs of HIV. Suboptimal levels of antiretroviral (ARVs) drugs in these difficult-to-penetrate viral reservoirs is one of the limitations of current antiretroviral therapy (ART) regimens. This study aimed to design and assess highly lipophilic ester prodrugs of dolutegravir (DTG) formulated with long-chain triglyceride (LCT) for delivery of DTG to the viral reservoir in mesenteric lymph and MLNs. A number of alkyl ester prodrugs of DTG were designed based on the predicted affinity to chylomicrons (CM), and the six most promising prodrugs were selected and synthesised. The synthesised prodrugs were further assessed for their intestinal lymphatic transport potential and biotransformation in biorelevant media in vitro and ex vivo. DTG and the most promising prodrug (prodrug 5) were then assessed in pharmacokinetic and biodistribution studies in rats. Although oral administration of 5 mg/kg of unmodified DTG (an allometrically scaled dose from humans) with or without lipids achieved concentrations above protein binding-adjusted IC90 (PA-IC90) (64 ng/mL) in most tissues, the drug was not selectively targeted to MLNs. The combination of lipophilic ester prodrug and LCT-based formulation approach improved the targeting selectivity of DTG to MLNs 4.8-fold compared to unmodified DTG. However, systemic exposure to DTG was limited, most likely due to poor intestinal absorption of the prodrug following oral administration. In vitro lipolysis showed a good correlation between micellar solubilisation of the prodrug and systemic exposure to DTG in rats in vivo. Thus, it is prudent to include in vitro lipolysis in the early assessment of orally administered drugs and prodrugs in lipidic formulations, even when intestinal lymphatic transport is involved in the absorption pathway. Further studies are needed to clarify the underlying mechanisms of low systemic bioavailability of DTG following oral administration of the prodrug and potential ways to overcome this limitation.

Willingness of Racially Diverse Young Adults Living with HIV to Participate in HIV Cure Research: A Cross-Sectional Survey in the United States

Nearly half of new HIV cases in the United States are among youth. Little is known about the willingness of young adults living with HIV (YLWH) to participate in HIV cure-related research. In 2021, we recruited 271 YLWH aged 18-29 for an online survey. We asked questions about willingness to participate in HIV cure research, perceived risks and benefits, acceptable trade-offs, and perceptions on analytical treatment interruptions. We conducted descriptive analyses to summarize data and bivariate analyses to explore correlations by demographics. Most respondents (mean age = 26) identified as men (86%) and Black Americans (69%). YLWH expressed high willingness to consider participating in cell- and gene-based approaches (75%) and immune-based approaches (71%). Approximately 45% would be willing to let their viral load become detectable for a period of time during an HIV cure study, 27% would not be willing, and 28% did not know. The social risk most likely to deter participation was the possibility of transmitting HIV to sex partners while off HIV medications (65% of respondents would be deterred a great deal or a lot). Compared to the 25-29 age group (n = 192), the 18-24 age group (n = 79) was more likely to indicate that having to disclose HIV status would matter a great deal in considering participation in HIV cure research (38% vs. 21%, p = .003). Inclusion and engagement of YLWH are critical for advancing novel HIV curative agents. Our article concludes with possible considerations for engaging YLWH in HIV cure research. Physical, clinical, and social risks will need to be kept to a minimum, and research teams will need to proactively mitigate the possibility of transmitting HIV to sex partners while off HIV medications.

The Effect of HIV Treatment Interruption on Subsequent Immunological Response

Recovery of CD4-positive T lymphocyte count after initiation of antiretroviral therapy (ART) has been thoroughly examined among people with human immunodeficiency virus infection. However, immunological response after restart of ART following care interruption is less well studied. We compared CD4 cell-count trends before disengagement from care and after ART reinitiation. Data were obtained from the East Africa International Epidemiology Databases to Evaluate AIDS (IeDEA) Collaboration (2001-2011; n = 62,534). CD4 cell-count trends before disengagement, during disengagement, and after ART reinitiation were simultaneously estimated through a linear mixed model with 2 subject-specific knots placed at the times of disengagement and treatment reinitiation. We also estimated CD4 trends conditional on the baseline CD4 value. A total of 10,961 patients returned to care after disengagement from care, with the median gap in care being 2.7 (interquartile range, 2.1-5.4) months. Our model showed that CD4 cell-count increases after ART reinitiation were much slower than those before disengagement. Assuming that disengagement from care occurred 12 months after ART initiation and a 3-month treatment gap, CD4 counts measured at 3 years since ART initiation would be lower by 36.5 cells/μL than those obtained under no disengagement. Given that poorer CD4 restoration is associated with increased mortality/morbidity, specific interventions targeted at better retention in care are urgently required.

The Essential Need for Trust When Transmission Risk Cannot Be Eliminated in HIV-Remission Trials

Analytic treatment interruption (ATI) is scientifically necessary in HIV-remission ("cure") studies to test the effects of new interventions. However, stopping antiretroviral treatment poses risks to research participants and their sexual partners. Ethical debate about whether and how to conduct such studies has largely centered on designing risk-mitigation strategies and identifying the responsibilities of research stakeholders. In this paper, we argue that because the possibility of HIV transmission from research participants to partners during ATI cannot practicably be eliminated-that is, it is ineliminable-the successful conduct of such trials ultimately depends on relationships of trust and trustworthiness. We describe our experiences with conducting and studying HIV-remission trials with ATI in Thailand to examine the strengths, complexities, and limitations of the risk-mitigation and responsibility approaches and to explore ways in which the building of trust-and trustworthiness-may help enhance the scientific, practical, and ethical dimensions of these trials.

Qualitative plasma viral load determination as a tool for screening of viral reservoir size in PWH

OBJECTIVES

Suppression of viral replication in patients on antiretroviral therapy (ART) is determined by plasma viral load (pVL) measurement. Whenever pVL reaches values below the limit of quantification, the qualitative parameter 'target detected' or 'target not detected' is available but often not reported to the clinician. We investigated whether qualitative pVL measurements can be used to estimate the viral reservoir size.

DESIGN

The study recruited 114 people with HIV (PWH) who are stable on ART between 2016 and 2018. The percentage of pVL measurements qualitatively reported as 'target detected' (PTD) within a 2-year period was calculated.

METHODS

t-DNA and US-RNA were used to estimate viral reservoir size and were quantified on peripheral blood mononuclear cells (PBMCs) using droplet digital PCR.

RESULTS

A median of 6.5 pVL measurements over a 2-year period was evaluated for each participant to calculate PTD. A positive correlation was found between t-DNA and PTD (r = 0.24; P = 0.011) but not between US-RNA and PTD (r = 0.1; P = 0.3). A significantly lower PTD was observed in PWH with a small viral reservoir, as estimated by t-DNA less than 66 copies/106 PBMCs and US-RNA less than 10 copies/106 PBMCs, compared with PWH with a larger viral reservoir (P = 0.001). We also show that t-DNA is detectable whenever PTD is higher than 56% and that ART regimen does not affect PTD.

CONCLUSION

Our study shows that PTD provides an efficient parameter to preselect participants with a small viral reservoir based on already available pVL data for future HIV cure trials.

Allogeneic MHC-matched T-cell receptor α/β-depleted bone marrow transplants in SHIV-infected, ART-suppressed Mauritian cynomolgus macaques

Allogeneic hematopoietic stem cell transplants (allo-HSCTs) dramatically reduce HIV reservoirs in antiretroviral therapy (ART) suppressed individuals. However, the mechanism(s) responsible for these post-transplant viral reservoir declines are not fully understood. Therefore, we modeled allo-HSCT in ART-suppressed simian-human immunodeficiency virus (SHIV)-infected Mauritian cynomolgus macaques (MCMs) to illuminate factors contributing to transplant-induced viral reservoir decay. Thus, we infected four MCMs with CCR5-tropic SHIV162P3 and started them on ART 6-16 weeks post-infection (p.i.), maintaining continuous ART during myeloablative conditioning. To prevent graft-versus-host disease (GvHD), we transplanted allogeneic MHC-matched α/β T cell-depleted bone marrow cells and prophylactically treated the MCMs with cyclophosphamide and tacrolimus. The transplants produced ~ 85% whole blood donor chimerism without causing high-grade GvHD. Consequently, three MCMs had undetectable SHIV DNA in their blood post-transplant. However, SHIV-harboring cells persisted in various tissues, with detectable viral DNA in lymph nodes and tissues between 38 and 62 days post-transplant. Further, removing one MCM from ART at 63 days post-transplant resulted in SHIV rapidly rebounding within 7 days of treatment withdrawal. In conclusion, transplanting SHIV-infected MCMs with allogeneic MHC-matched α/β T cell-depleted bone marrow cells prevented high-grade GvHD and decreased SHIV-harboring cells in the blood post-transplant but did not eliminate viral reservoirs in tissues.

OUP accepted manuscript

Background

Methods

Results

Conclusions

High rate of long-term clinical events after antiretroviral therapy resumption in HIV-positive patients exposed to antiretroviral therapy interruption

OBJECTIVE

We analyzed the incidence rate of long-term events in patients on antiretroviral therapy (ART) previously exposed to therapy interruption.

DESIGN

A single-center cohort study involving participants in ART interruptions (ARTI) clinical trials (n = 10) was conducted.

METHODS

Non-AIDS events after ART resumption were analyzed. A control group not exposed to ARTI was randomly selected from the same cohort and a propensity score of belonging to ARTI group was estimated based on age, sex, CD4+ nadir value, time from HIV diagnosis to ARTI, time from HIV diagnosis to starting ART and time of suppressed viral load, and used to adjust effect estimates.

RESULTS

One hundred and eighty-one patients were included, 136 in ARTI and 45 in the control arm. Median time of known HIV-1 infection was 21 years and median time from ART resumption to first non-AIDS event was 5.2 years. A significantly higher proportion of patients with ARTI had an event as compared with control group [raw percentages: 43% (n = 53) vs. 23% (n = 10), P = 0.015]. These differences were confirmed when only the non-AIDS events occurring after ART resumption were analyzed [adjusted hazard ratio (aHR) = 2.43, 95% confidence interval (CI) 1.15-5.12]. The logistic model adjusted for the propensity score indicated that patients with an ARTI had a four-fold higher risk of having at least one non-AIDS event (P = 0.002).

CONCLUSION

We found a higher risk of having at least one non-AIDS event years after ART resumption in HIV-infected patients exposed to ARTI as compared with controls. These data should be taken into consideration for future functional cure clinical trials.

CD8 Effector T Cells Function Synergistically With Broadly Neutralizing Antibodies to Enhance Suppression of HIV Infection

HIV-specific CD8 T cells and broadly neutralizing antibodies (bNAbs) both contribute to the control of viremia, but in most cases, neither can completely suppress viral replication. To date, therapeutic vaccines have not been successful in eliciting HIV-specific CD8 T cell or bNAb responses that are capable of preventing long-term viral rebound upon ART cessation. These challenges suggest that a combinatorial approach that harnesses both bNAbs and CD8 T cell responses may be necessary for long term control of viral replication. In this study we demonstrate a synergistic interaction between CD8 T cells and bNAbs using an in vitro model. Our data suggest that this combinatorial approach is very effective at suppressing viral replication in vitro and should be considered in future therapeutic studies.

Impact of Analytical Treatment Interruption on Burden and Diversification of HIV Peripheral Reservoir: A Pilot Study

BACKGROUND

If analytical antiretroviral-treatment (ART) interruption (ATI) might significantly impact quantitative or qualitative peripheral-total HIV-DNA is still debated.

METHODS

Six chronically HIV-1 infected patients enrolled in APACHE-study were analysed for peripheral-total HIV-DNA and residual viremia, major-resistance-mutations (MRMs) and C2-V3-C3 evolution at pre-ATI (T1), during ATI (T2) and at achievement of virological success after ART-resumption (post-ATI, T3). These data were obtained at three comparable time-points in five chronically HIV-1 infected patients on suppressive ART for ≥1 year, enrolled in MODAt-study.

RESULTS

At T1, APACHE and MODAt individuals had similar peripheral-total HIV-DNA and residual viremia (p = 0.792 and 0.662, respectively), and no significant changes for these parameters were observed between T1 and T3 in both groups. At T1, 4/6 APACHE and 2/5 MODAt carried HIV-DNA MRMs. MRMs disappeared at T3 in 3/4 APACHE. All disappearing MRMs were characterized by T1 intra-patient prevalence <80%, and mainly occurred in APOBEC3-related sites. All MRMs persisted over-time in the 2 MODAt. C2-V3-C3 genetic-distance significantly changed from T1 to T3 in APACHE individuals (+0.36[0.11-0.41], p = 0.04), while no significant changes were found in MODAt. Accordingly, maximum likelihood trees (bootstrap > 70%) and genealogical sorting indices (GSI > 0.50 with p-value < 0.05) showed that T1 C2-V3-C3 DNA sequences were distinct from T2 and T3 viruses in 4/6 APACHE. Virus populations at all three time-points were highly interspersed in MODAt.

CONCLUSIONS

This pilot study indicates that short ATI does not alter peripheral-total HIV-DNA burden and residual viremia, but in some cases could cause a genetic diversification of peripheral viral reservoir in term of both MRMs rearrangement and viral evolution.

Analytical Treatment Interruption in HIV Trials: Statistical and Study Design Considerations

Purpose of Review

Analytical treatment interruption (ATI) remains an essential component in clinical studies investigating novel agents or combination treatment strategies aiming to induce HIV treatment-free remission or long-term viral control. We provide an overview on key study design aspects of ATI trials from the perspective of statisticians.

Recent Findings

ATI trial designs have evolved towards shorter treatment interruption phases and more frequent viral load monitoring aiming to reduce prolonged viremia risks. Criteria for ART resumption have evolved as well. Common outcome measures in modern ATI trials include time to viral rebound, viral control, and viral set point.

Summary

Design of the ATI component in HIV clinical trials is driven by the scientific question and the mechanism of action of the intervention being investigated.

Ethics of HIV cure research: an unfinished agenda

Background

The pursuit of a cure for HIV is a high priority for researchers, funding agencies, governments and people living with HIV (PLWH). To date, over 250 biomedical studies worldwide are or have been related to discovering a safe, effective, and scalable HIV cure, most of which are early translational research and experimental medicine. As HIV cure research increases, it is critical to identify and address the ethical challenges posed by this research.

Methods

We conducted a scoping review of the growing HIV cure research ethics literature, focusing on articles published in English peer-reviewed journals from 2013 to 2021. We extracted and summarized key developments in the ethics of HIV cure research. Twelve community advocates actively engaged in HIV cure research provided input on this summary and suggested areas warranting further ethical inquiry and foresight via email exchange and video conferencing.

Discussion

Despite substantial scholarship related to the ethics of HIV cure research, additional attention should focus on emerging issues in six categories of ethical issues: (1) social value (ongoing and emerging biomedical research and scalability considerations); (2) scientific validity (study design issues, such as the use of analytical treatment interruptions and placebos); (3) fair selection of participants (equity and justice considerations); (4) favorable benefit/risk balance (early phase research, benefit-risk balance, risk perception, psychological risks, and pediatric research); (5) informed consent (attention to language, decision-making, informed consent processes and scientific uncertainty); and (6) respect for enrolled participants and community (perspectives of people living with HIV and affected communities and representation).

Conclusion

HIV cure research ethics has an unfinished agenda. Scientific research and bioethics should work in tandem to advance ethical HIV cure research. Because the science of HIV cure research will continue to rapidly advance, ethical considerations of the major themes we identified will need to be revisited and refined over time.

Participant Perspectives and Experiences Entering an Intensively Monitored Antiretroviral Pause: Results from the AIDS Clinical Trials Group A5345 Biomarker Study

The AIDS Clinical Trials Group (ACTG) A5345 study included an intensively monitored antiretroviral pause (IMAP), during which a cohort of participants temporarily stopped antiretroviral treatment during chronic HIV infection. We surveyed participant perceptions and understanding of A5345 using a cross-sectional sociobehavioral questionnaire. Participants completed the baseline questionnaire either before or after initiating the study's IMAP. Questionnaire responses were linked to existing demographic data. Quantitative responses were analyzed overall and stratified by IMAP status. Open-ended responses were analyzed using conventional content analysis. Thirty-two participants completed the baseline sociobehavioral questionnaire. Half (n = 16) completed it before (i.e., pre-IMAP initiation group) and half (n = 16) after IMAP initiation (i.e., post-IMAP initiation group). Eight pre-IMAP initiation respondents (50%) and 11 post-IMAP respondents (69%) responded "yes" when asked if they perceived any direct benefits from participating in A5345. Perceived societal-level benefits included furthering HIV cure-related research and helping the HIV community. Perceived personal-level benefits included the opportunity to learn about the body's response to IMAP and financial compensation. The majority of respondents-13 from each group (81% of each)-reported risks from participation, for example, viral load becoming detectable. A5345 participants perceived both societal- and personal-level benefits of study participation. While the majority of survey respondents perceived participatory risks, nearly one in five did not. Key messages pertaining to study-related risks and benefits may need to be clarified or reiterated periodically throughout follow-up in HIV cure-related studies with IMAPs. Clinical Trail Registration Number: NCT03001128.

Launching a multidisciplinary European collaboration towards a cure for HIV: The EU2Cure Consortium

We felt the urgency to launch the EU2Cure Consortium to support research and find a cure for the human immunodeficiency virus (HIV) infection through intensified collaboration within Europe. This consortium is open to stakeholders on cure in Europe from academia and the community to connect. The aim of this consortium is to intensify the research collaboration amongst European HIV cure groups and the community and facilitate interactions with other academic and community cure consortia, private parties, and policy makers. Our main aim is to create a European research agenda, data sharing, and development of best practice for clinical and translational science to achieve breakthroughs with clinically feasible HIV cure strategies. This consortium should also enable setting up collaborative studies accessible to a broader group of people living with HIV. Besides reservoir studies, we have identified three overlapping scientific interests in the consortium that provide a starting point for further research within a European network: developing “shock and kill” cure strategies, defining HIV cure biomarkers, and connecting cure cohorts. This strategy should aid stakeholders to sustain progress in HIV cure research regardless of coincidental global health or political crises.

Kinetics of Plasma HIV Rebound in the Era of Modern Antiretroviral Therapy

Historical data regarding time to viral rebound following analytical treatment interruption (ATI) have been used to determine therapeutic efficacy in HIV cure trials; however, such data were collected from studies conducted a decade or more ago and included participants receiving older antiretroviral therapy (ART) regimens with infrequent virologic monitoring. We conducted a study of 22 HIV-infected participants receiving modern ART to determine the kinetics of plasma viral rebound following ATI. Our data suggest that modern ART does not alter kinetics of viral rebound when compared to previous regimens and that immunologic interventions may be necessary to achieve ART-free virologic remission. Clinical Trials Registration ClinicaTrials.gov identifier: NCT03225118.

Acceptability, motivation and the prospect of cure for people living with HIV and their healthcare providers in HIV cure-focused treatment interruption studies

Background

Analytical treatment interruptions (ATI) are commonly used clinical endpoints to assess interventions aimed at curing HIV or achieving antiretroviral therapy (ART)-free HIV remission. Understanding the acceptability of ATI amongst people living with HIV (PLHIV) and their HIV healthcare providers (HHP) is limited.

Methods

Two online surveys for PLHIV and HHP assessed awareness and acceptability of ATI, and understanding of the prospect for HIV cure in the future. Responses were collected from July 2017–January 2018. A descriptive analysis was performed and similar questions across the two surveys were compared using χ squared test.

Results

442 PLHIV and 144 HHP completed the survey. 105/400 (26%) PLHIV had ever interrupted ART, 8% of which were in a clinical trial. Altruistic motivations were drivers of participation of PLHIV in cure related research. 81/135 (60%) HHP would support their patients wishing to enrol in an HIV cure-focused trial, but fewer would promote and allow such participation (25% and 31% respectively). Compared to HHP, PLHIV were more likely to believe that an HIV cure would be achievable within 10 years (55% vs. 19%, p < 0.001), had less awareness of ATI (46% vs. 62%, p < 0.001) and were less likely to have had experience of either participation or enrolment in an ATI study (5% vs. 18%, p < 0.001)

Conclusion

PLHIV were more optimistic about the potential for HIV cure. HHP had more direct experience with HIV cure-focused studies. Educational strategies are required for both groups to increase understanding around ATIs in HIV cure research but should be tailored specifically to each group.

Time for revolution? Enhancing meaningful involvement of people living with HIV and affected communities in HIV cure-focused science

INTRODUCTION

Involving affected communities and people living with HIV (PLHIV) in HIV cure-focused clinical trials has ethical and practical benefits. However, there can be barriers to meaningful involvement of 'lay people' in scientific research meaning community consultation is often limited or tokenistic. This paper reports on an Australian project, the INSPIRE project (Improve, Nurture and Strengthen education, collaboration, and communication between PLHIV and Researchers), which aimed to explore barriers and enablers to enactment of the principles of meaningful involvement of PLHIV (MIPA) and affected communities in HIV cure-focused research.

METHODS

The project involved a workshop attended by 40 stakeholders involved in HIV care, research or advocacy including PLHIV, community organizations, basic scientists, and clinicians. The workshop involved a facilitated discussion about community involvement in a hypothetical HIV cure-focused clinical trial. Data were collected through notetaking and video recordings. Qualitative, thematic analysis was undertaken to organize the data and identify core themes related to MIPA.

RESULTS

Workshop discussions revealed community stakeholders often feel their involvement in HIV clinical research is undervalued, evidenced by limited financial remuneration and minimal capacity to influence the research design or processes. Building long-term, formal and informal relationships between community organizations, PLHIV, researchers and research teams or laboratories was identified as a strategy to support MIPA at all stages of a clinical trial, from design to dissemination of findings.

CONCLUSIONS

Enacting MIPA principles in HIV cure-focused research requires a better understanding of the potential to improve research outcomes and ensure quality in the research process.

Long-term clinical, virological and immunological outcomes following planned treatment interruption in HIV-infected children

OBJECTIVES

Planned treatment interruption (PTI) of antiretroviral therapy (ART) in adults is associated with adverse outcomes. The PENTA 11 trial randomized HIV-infected children to continuous ART (CT) vs. CD4-driven PTIs. We report 5 years' follow-up after the end of main trial.

METHODS

Post-trial, all children resumed ART. Clinical, immunological, virological and treatment data were collected annually. A sub-study investigated more detailed immunophenotype. CT and PTI arms were compared using intention-to-treat. Laboratory parameters were compared using linear regression, adjusting for baseline values; mixed models were used to include all data over time.

RESULTS

In all, 101 children (51 CT, 50 PTI) contributed a median of 7.6 years, including 5.1 years of post-trial follow-up. Post-trial, there were no deaths, one pulmonary tuberculosis and no other CDC stage B/C events. At 5 years post-trial, 90% of children in the CT vs. 82% in the PTI arm had HIV RNA < 50 copies/mL (P = 0.26). A persistent increase in CD8 cells was observed in the PTI arm. The sub-study (54 children) suggested that both naïve and memory populations contributed to higher CD8 cells following PTI. Mean CD4/CD8 ratios at 5 years post-trial were 1.22 and 1.08 in CT and PTI arms, respectively [difference (CT - PTI) = -0.15; 95% CI: -0.34-0.05), P = 0.14]. The sub-study also suggested that during the trial and at early timepoints after the end of the trial, reduction in CD4 in the PTI arm was mainly from loss of CD4 memory cells.

CONCLUSIONS

Children tolerated PTI with few long-term clinical, virological or immunological consequences.

Impact of fluctuation in frequency of human immunodeficiency virus/simian immunodeficiency virus reactivation during antiretroviral therapy interruption

Antiretroviral therapy (ART) provides effective control of human immunodeficiency virus (HIV) replication and maintains viral loads of HIV at undetectable levels. Interruption of ART causes rapid recrudescence of HIV plasma viremia due to reactivation of latently HIV-infected cells. Here, we characterize the timing of both the initial and subsequent successful viral reactivations following ART interruption in macaques infected with simian immunodeficiency virus (SIV). We compare these to previous results from HIV-infected patients. We find that on average the time until the first successful viral reactivation event is longer than the time between subsequent reactivations. Based on this result, we hypothesize that the reactivation frequency of both HIV and SIV may fluctuate over time, and that this may impact the treatment of HIV. We develop a stochastic model incorporating fluctuations in the frequency of viral reactivation following ART interruption that shows behaviours consistent with the observed data. Furthermore, we show that one of the impacts of a fluctuating reactivation frequency would be to significantly reduce the efficacy of 'anti-latency' interventions for HIV that aim to reduce the frequency of reactivation. It is therefore essential to consider the possibility of a fluctuating reactivation frequency when assessing the impact of such intervention strategies.

Antiretroviral Therapy Interruption (ATI) in HIV-1 Infected Patients Participating in Therapeutic Vaccine Trials: Surrogate Markers of Virological Response

A functional Human immunodeficiency Virus (HIV) cure has been proposed as an alternative to antiretroviral treatment for life, and therapeutic vaccines represent one of the most promising approaches. The goal of therapeutic vaccination is to augment virus-specific immune responses that have an impact on HIV viral load dynamics. To date, the agreed feature to evaluate the effects of these therapeutic interventions is analytical antiretroviral treatment interruption (ATI), at least until we find a reliable biomarker that can predict viral control. Different host, immunologic, and virologic markers have been proposed as predictors of viral control during ATI after therapeutic interventions. This review describes the relevance of ATI and the different surrogate markers of virological control assessed in HIV therapeutic vaccine clinical trials.

Perspectives on Analytical Treatment Interruptions in People Living with HIV and Their Health Care Providers in the Landscape of HIV Cure-Focused Studies

Analytical treatment interruptions (ATIs) aim to assess effects of HIV cure-focused interventions, but poses potential risks. Understanding of ATI acceptability among people living with HIV (PLHIV) and their HIV health care providers (HHP) is limited. Two international online surveys for PLHIV and HHP assessed understanding and acceptability of monitoring strategies during ATI. Survey items included the following: frequency of CD4, viral load (VL) and clinical assessment, CD4 and VL threshold to restart antiretroviral therapy (ART), acceptability of detectable viremia during ATI, and potential risks of ATI. Responses were collected from July 2017 to January 2018, and a descriptive analysis was performed. Responses to questions asked in both surveys were compared by χ² test. Four hundred forty-two completed the PLHIV survey: 22% identified as female, 39% older than 50 years of age, and 64% identified as gay/homosexual/lesbian. Ninety-five percent were on ART, of which 83% reported an undetectable VL. The preferred frequency of CD4, VL, and clinical monitoring during ATI was monthly. Thirty-five percent of respondents preferred VL to remain undetectable during ATI and would not accept any sustained period of viremia, compared to 18% of 144 HHP (p < .01). Having previously interrupted ART predicted preference for VL to remain undetectable during ATI (odds ratio 0.6, p = .05). Both clinicians and PLHIV were concerned about HIV transmission during ATI. Our work demonstrates that PLHIV expectations of ATI in cure-focused clinical trials do not align with current practices, with PLHIV less accepting of viremia during ATI and preferring less frequent monitoring. Clear education messages and careful consent processes need to be developed in relationship to ATIs in HIV cure research.

Long-term efficacy and safety of nevirapine-containing regimens in virologically suppressed patients: a 17-year follow up

Background: To evaluate long term outcomes in patients maintaining a NVP based regimen for more than 10 years.Materials and methods: Retrospective, multicenter, cohort study including virologically suppressed patients, currently receiving a NVP-based regimen that had been started at least 10 years previously. Demographic, clinical, and analytical variables were recorded.Results: Two hundred and seventy four subjects were included. Median (IQR) follow up was 17.1 (13.8-18.5) years. Dyslipidemia (29.9%), hypertension (11.4%) and diabetes (8%) were the most common reported co-morbidities. After a median of 17 years of follow-up we observed a significant increase in general health markers such as hemoglobin and CD4 cells (all p<0.001) as well as a significant reduction in CD8 and ALT [-111 cells/uL (-346.5-151) p 0.003 and ALT median (IQR) -4.2 (-18.5-4) p<0.001 respectively]. LDL-c and serum triglyceride levels decreased significantly [-0,1 (-1-0.6) p:<0.001 and -0,3 (-1.2-0.4) p:0.002 respectively]. HDL-c increased significantly 0.3 (00.5-0.6). Median (IQR) time with persistent HIV VL <50 copies was 16 (13-18) years. During follow up, subjects presented with median (IQR) 1 (0-2) blip (HIV VL >50<1000 copies/ml).Conclusions: Based on the extensive experience as well as a good tolerance and efficacy profile, NVP should be considered for treatment continuation in those patients already receiving this inexpensive generic drug.

Rapid viral rebound after analytical treatment interruption in patients with very small HIV reservoir and minimal on-going viral transcription

INTRODUCTION

Viral remission after analytical treatment interruption (ATI), termed post-treatment control, has been described in a small proportion of HIV-positive patients. This phenomenon has been separately associated to both low levels of HIV-1 proviral DNA as well as cell-associated RNA. We investigated whether the combination of both parameters could help predict delayed viral rebound after treatment interruption (TI).

METHODS

We conducted an open single-arm ATI study in four Belgian HIV reference centres from January 2016 to July 2018. Eligible participants were adults who had fewer than 50 HIV-1 RNA copies/mL for more than two years, more than 500 CD4 cells/µL for more than three months, and were in general good health. Consenting participants who had fewer than 66 copies total HIV-1 DNA (t-DNA) and fewer than 10 copies cell-associated HIV-1 unspliced RNA (US-RNA) per million peripheral blood mononuclear cells (PBMCs), interrupted therapy and were monitored closely. Antiretroviral therapy (ART) was resumed after two consecutive viral loads exceeding 1000 copies or one exceeding 10,000 copies/mL. The primary outcome was the proportion of participants with fewer than 50 HIV-1 RNA copies/mL 48 weeks after TI. Secondary outcomes were time to viral rebound, the frequency of serious adverse events (AEs) and evolution of t-DNA and US-RNA after TI.

RESULTS

All 16 consenting participants who interrupted therapy experienced rapid viral rebound two to eight weeks after TI. No serious AEs were observed. Levels of t-DNA and US-RNA increased after TI but returned to pre-ATI levels after treatment restart. None of the studied demographic, clinical and biological parameters were predictive of time of viral rebound.

CONCLUSIONS

The combination of low levels of t-DNA and US-RNA in PBMCs, corresponding respectively to a small and transcriptionally silent viral reservoir, is not predictive of viral remission after TI in patients on ART.

10-year outcome of temporary structured treatment interruption (STI) among HIV-1-infected patients: An observational study in a single medical center

BACKGROUND

Lifelong antiretroviral therapy (ART) is recommended for HIV-1 infected patients but may lead to intolerance or poor adherence. Structured treatment interruption (STI) is a strategy for drug holiday or to boost HIV-specific immunity. But the long-term outcome of STI was never reported in literature.

METHODS

This is a single-center observational study. We followed the HIV-infected patients who already had a stable viral suppression and voluntarily started temporary STI with a fixed 12-week interval after counseling, evaluation and education. HIV-1-specific T cell response was also measured in some patients.

RESULTS

Totally 34 HIV-infected patients received temporary STI since July, 2006. 18 patients completed 10-year follow-up. All patients received protease inhibitors (PI)-based ART before and during temporary STI. The patients received temporary STI with a period of 36-85 weeks. All of them reached viral suppression after 12 weeks of restarting continuous ART. No viral rebound or opportunistic disease was recorded during follow-up. No adverse event or comorbidity was attributed to STI. The plasma viral load (PVL) at the end of STI was significantly lower than baseline PVL in patients with a longer duration of STI (≤36 weeks vs. >36 weeks, P = 0.005). The T cell response study revealed that cyclically increased HIV-1-specific T cell response after starting STI in patients with baseline CD4+ count >350/μL.

CONCLUSION

Temporary STI may not lead to worse long-term outcome among highly selected patients. The policy may partially control viral replication through reminding the HIV-1 specific T cell immunity.