Recommendations for analytical antiretroviral treatment interruptions in HIV research trials-report of a consensus meeting

Early antiretroviral therapy in SIV-infected rhesus macaques reveals a multiphasic, saturable dynamic accumulation of the rebound competent viral reservoir

The rebound competent viral reservoir (RCVR)-virus that persists during antiretroviral treatment (ART) and can reignite systemic infection when treatment is stopped-is the primary barrier to eradicating HIV. We used time to initiation of ART during primary infection of rhesus macaques (RMs) after intravenous challenge with barcoded SIVmac239 as a means to elucidate the dynamics of RCVR establishment in groups of RMs by creating a multi-log range of pre-ART viral loads and then assessed viral time-to-rebound and reactivation rates resulting from the discontinuation of ART after one year. RMs started on ART on days 3, 4, 5, 6, 7, 9 or 12 post-infection showed a nearly 10-fold difference in pre-ART viral measurements for successive ART-initiation timepoints. Only 1 of 8 RMs initiating ART on days 3 and 4 rebounded after ART interruption despite measurable pre-ART plasma viremia. Rebounding plasma from the 1 rebounding RM contained only a single barcode lineage detected at day 50 post-ART. All RMs starting ART on days 5 and 6 rebounded between 14- and 50-days post-ART with 1-2 rebounding variants each. RMs starting ART on days 7, 9, and 12 had similar time-to-measurable plasma rebound kinetics despite multiple log differences in pre-ART plasma viral load (pVL), with all RMs rebounding between 7- and 16-days post-ART with 3-28 rebounding lineages. Calculated reactivation rates per pre-ART pVL were highest for RMs starting ART on days 5, 6, and 7 after which the rate of accumulation of the RCVR markedly decreased for RMs treated on days 9 and 12, consistent with multiphasic establishment and near saturation of the RCVR within 2 weeks post infection. Taken together, these data highlight the heterogeneity of the RCVR between RMs, the stochastic establishment of the very early RCVR, and the saturability of the RCVR prior to peak viral infection.

"This Is Actually a Really Unique Moment in Time": Navigating Long-Acting HIV Treatment and HIV Cure Research with Analytical Treatment Interruptions-A Qualitative Interview Study in the United States

Advancements in long-acting (LA) HIV treatment and cure research with analytical treatment interruptions (ATIs) have generated important scientific and implementation questions. There is an urgent need to examine challenges navigating the evolving HIV treatment and cure research landscape. From August to October 2022, we conducted 26 semistructured interviews with biomedical researchers and community members representing a predominantly woman demographic to explore the complexity of navigating the rapidly evolving HIV therapeutic and HIV cure research landscape. We purposively sampled individuals recruited from the AIDS Clinical Trials Group and the Martin Delaney Collaboratories for HIV Cure Research. Audio files were transcribed verbatim and analyzed through a thematic approach, using an inductive and iterative process. Among 26 participants, 10 were biomedical researchers and 16 community members, including 11 were people with HIV. Three main themes emerged: (1) We are at a pivotal moment in the evolving landscape of HIV therapeutics and LA HIV treatment and HIV cure research should not be siloed but considered together; (2) There are challenges with engagement in HIV cure research and in switching between oral daily antiretroviral treatment and LA formulations and, mainly, the prolonged pharmacokinetic tail of these compounds matched with limited patient education about their impacts; and (3) There are unique opportunities as a result of this evolving therapeutic landscape, including the key role of decision support for people with HIV, centering around patient autonomy, and the need to learn from the lived experiences of people with HIV who choose LA treatment and/or participation in HIV cure research. Despite a bias toward the woman gender, our study identifies key considerations for navigating concurrent LA HIV treatment and HIV cure research with ATIs from both community members and biomedical researchers' perspectives. Achieving optimal HIV control remains a formidable challenge, necessitating robust interdisciplinary collaborations and engagement with key stakeholders.

Evaluation of HIV-1 DNA levels among adolescents living with perinatally acquired HIV-1 in Yaounde, Cameroon: A contribution to paediatric HIV cure research in Sub-Saharan Africa

Background

With the advent of antiretroviral therapy (ART), most children living with HIV in sub-Saharan Africa (SSA) are growing toward adolescence, with scarcity of evidence on the size of viral reservoirs to enhance paediatric cure research strategies. This study aims to compare HIV-1 proviral DNA levels according to virological response among adolescents living with perinatally acquired HIV-1 (ALPHIV) and identify associated-factors in the Cameroonian context.

Methods

In this observational cohort study, HIV-1 RNA viremia and CD4+ T-cell count were assessed through RT-PCR and flow cytometry respectively at three time-points over 18 months of observation. At the third time-point, 80 randomly-selected participants were classified as with viremia (≥50 HIV-1 copies/mL; n = 40) or without viremia (<50 HIV-1 copies/mL; n = 40); immune-competent (≥500 CD4+ T cells/mm3) or immunocompromised (<500 CD4+ T cells/mm3). Among these participants, total HIV-1 DNA load was quantified through droplet digital PCR using Bio-Rad QX200.

Results

Of the 80 randomly-selected adolescents, median [IQR] age was 15 (13-17) years, 56.2% were female, duration on ART was 9.3 [5.4-12.2] years. Among the 40 viremic ones (median viremia 7312 [283-71482]) HIV-1 copies/ml, 75.0% (30/40) were in virological failure (≥1000 HIV-1 copies/ml), while median of CD4 T cells were 494 [360-793] cell/mm3 with 48.8% (39/80) immunocompromised. No significant variation in HIV-1 RNA viremia and CD4 T cell count was observed between the three time-points, and 13.7% (11/80) adolescents remained aviremic and immune-competent throughout (stable adolescents). A positive and moderate correlation (r = 0.59; p < 0.001) was found between HIV-1 DNA levels and HIV- 1 RNA viremia. Regarding the CD4 T cell count, a negative and weak correlation (r = -0.28; p = 0.014) was found with HIV-1 DNA loads only among adolescents with viremia. Starting ART within the first year of life, ART for over 9 years and aviremia appear as predictors of low HIV-1 DNA loads.

Conclusion

Among ALPHIV, high HIV-1 RNA indicates an elevated viral reservoir size, representing a drawback to cure research. Interestingly, early ART initiation and longer ARTduration lead to sustained viral control and limited HIV-1 reservoir size. As limited size of viral reservoir appears consistent with viral control and immune competence, adolescents with sustained viral control (about 14% of this target population) would be candidates for analytical ART interruptions toward establishing paediatric post-treatment controllers in SSA.

People with HIV at the end-of-life and their next-of-kin/loved ones are willing to participate in interventional HIV cure-related research

INTRODUCTION

The Last Gift study at the University of California San Diego (UCSD), United States enrolls terminally ill people with HIV (PWH) in HIV cure research.

METHODS

From 2017 to 2022, we conducted surveys with Last Gift participants and their next-of-kin/loved ones to evaluate willingness to participate in different types of HIV cure research at the end of life (EOL). We analyzed willingness data descriptively.

RESULTS

We surveyed 17 Last Gift participants and 17 next-of-kin/loved ones. More than half of Last Gift participants ( n  = 10; 58.8%) expressed willingness to participate in studies involving totally new treatments or approaches ('first-in-human' studies), a combination of different approaches, the use of unique antibodies, proteins or molecules, or therapeutic vaccines. Under one-quarter of Last Gift participants ( n  = 4; 23.5%) expressed willingness to participate in research involving interventions that may shorten their life expectancy to benefit medical research. Most Last Gift participants and their next-of-kin/loved ones also expressed high acceptance for various types of donations and biopsies at the EOL (e.g. hair donations and skin, lymph node or gut biopsies).

DISCUSSION

Knowing whether people would be willing to participate in different types of EOL HIV cure research can help inform the design of future innovative studies. As a research community, we have a duty to design studies with adequate safeguards to preserve the public trust in research and honor PWH's important gift to humanity.

Participant experiences in a combination HIV cure-related trial with extended analytical treatment interruption in San Francisco, United States

BACKGROUND

There is limited systematic information available about the perspectives of participants enrolled in intensive combination HIV cure-related trials inclusive of an extended analytical treatment interruption (ATI).

OBJECTIVE

To assess and understand experiences of people with HIV involved in a combination HIV cure-related trial with an extended ATI.

METHODS

The trial included five interventions and was followed by an ATI lasting up to 52 wk. From 2022 - 2023, we conducted in-depth interviews with study participants following their extended ATIs. Interviews were audio-recorded, transcribed, and analyzed via conventional thematic analysis.

RESULTS

We interviewed seven participants. The majority were male, White, and non-Hispanic, with a median age of 37 years. Trust in the research team, scientific altruism and hope of becoming a post-intervention controller were key motivators for joining the trial. Interviewees reported being satisfied with their decision to participate in the trial and the extended ATI. Most recounted feelings of worry related to viral rebound during the ATI. Participants reported both defeat and relief with ART restart. Four faced challenges with protecting partners from HIV during their ATI, such as trying to find out if their partner(s) were using pre-exposure prophylaxis.

CONCLUSIONS

Our findings demonstrate potential improvements for future ATI trial participant experiences, such as more robust resources for psychosocial support and partner protections. Dedicating greater effort to understanding participant ATI experiences can inform the design of future participant-centered HIV cure trial protocols.

The Importance of Social Engagement in the Development of an HIV Cure: A Systematic Review of Stakeholder Perspectives

As research into the development of an HIV cure gains prominence, assessing the perspectives of stakeholders becomes imperative. It empowers stakeholders to determine priorities and influence research processes. We conducted a systematic review of the empirical literature on stakeholder perspectives. PubMed, Embase, Web of Science, and Scopus were searched for empirical, peer-reviewed articles, published before September 2022. Our analysis of 78 papers showed that stakeholders could be divided into three categories: people with HIV, key populations, and professionals. Following thematic synthesis, two main themes were distinguished: stakeholders' perspectives on HIV cure research and stakeholders' perspectives on HIV cure. Research on perspectives on HIV cure research showed that stakeholders' hypothetical willingness to participate (WTP) in HIV cure research was relatively high, while actual WTP was found to be lower. Studies also identified associated (individual) characteristics of hypothetical WTP, as well as facilitators and barriers to hypothetical participation. Additionally, we reported research on experiences of actual HIV cure research participation. Our analysis of stakeholder perceptions of HIV cure showed that most stakeholders preferred a cure that could eliminate HIV and outlined positive associated impacts. Furthermore, we observed that most included studies were conducted among PWHIV, and in the Global North. To empower stakeholders, we recommend that future research include an even greater diversity of stakeholders and incorporate theories of behavior to further explore how stakeholders decide to meaningfully engage in every stage of HIV cure research.

Participant experiences in HIV cure-directed trial with an extended analytical treatment interruption in Philadelphia, United States

BACKGROUND

A feature of HIV cure trials is the need to interrupt treatment to test the efficacy of experimental interventions-a process known as analytical treatment interruptions (ATIs).

OBJECTIVES

We report the experiences of participants after they completed an extended ATI.

METHODS

From April to November 2022, we conducted post-ATI in-depth interviews with BEAT2 clinical trial (NCT03588715) participants who stopped ART while receiving an immunotherapy regimen. We used conventional content analysis to code the data.

RESULTS

We conducted interviews with 11 Black/African American and three White/Caucasian participants (11 males, two females, and one transgender woman). The mean ATI was 38 weeks. Participants noted several significant experiences surrounding the interventions' side effects, ATI, and returning to medication. Some participants had positive experiences with their ATI. Other participants were nervous during the ATI. Rising viral loads led some to feel a sense of failure. Although trial experiences were heterogeneous, participants unanimously had positive interactions with the clinical trial staff which facilitated their retention in the trial. Participants shared their experiences with the trial, including changes in expectations, experiences with experimental interventions and procedures, compensation as a measure of respect, effort, transportation, and effects of COVID-19 during the trial. Based on these results, we provide considerations for the conduct of future HIV cure-directed clinical trials involving ATIs.

CONCLUSIONS

Managing expectations, focusing on participants' contributions, and providing support to reduce feelings of having failed the research team and/or the HIV community following viral rebound should be part of HIV cure trial design. Discussing the mental health impact of rebound during consent, distinct from risk, is needed. Continued efforts to understand how people with HIV experience ATIs will improve future designs of HIV cure clinical trials.

A partner protection package for HIV cure-related trials involving analytical treatment interruptions

Analytical treatment interruptions (ATIs) have become a key methodological approach to evaluate the effects of experimental HIV cure-related research interventions. During ATIs, sex partners of trial participants might be at risk of acquiring HIV. This risk raises both ethical and feasibility concerns about ATI trials. We propose a partner protection package (P3) approach to address these concerns. A P3 approach would provide guidance to investigators, sponsors, and those who are designing and implementing context-specific partner protections in HIV cure-related trials involving ATIs. The approach would also help assure institutional review boards, trial participants, and communities that ATI trials with a P3 would provide appropriate partner protections. We offer a prototype P3 framework that delineates three basic considerations for protecting participants' sex partners during ATI trials: (1) ensuring the scientific and social value of the ATI and the trial, (2) reducing the likelihood of unintended HIV transmission, and (3) ensuring prompt management of any acquired HIV infection. We outline possible ways of implementing these basic considerations.

Timing of initiation of anti-retroviral therapy predicts post-treatment control of SIV replication

One approach to 'functional cure' of HIV infection is to induce durable control of HIV replication after the interruption of antiretroviral therapy (ART). However, the major factors that determine the viral 'setpoint' level after treatment interruption are not well understood. Here we combine data on ART interruption following SIV infection for 124 total animals from 10 independent studies across 3 institutional cohorts to understand the dynamics and predictors of post-treatment viral control. We find that the timing of treatment initiation is an important determinant of both the peak and early setpoint viral levels after treatment interruption. During the first 3 weeks of infection, every day of delay in treatment initiation is associated with a 0.22 log10 copies/ml decrease in post-rebound peak and setpoint viral levels. However, delay in initiation of ART beyond 3 weeks of infection is associated with higher post-rebound setpoint viral levels. For animals treated beyond 3 weeks post-infection, viral load at ART initiation was the primary predictor of post-rebound setpoint viral levels. Potential alternative predictors of post-rebound setpoint viral loads including cell-associated DNA or RNA, time from treatment interruption to rebound, and pre-interruption CD8+ T cell responses were also examined in the studies where these data were available. This analysis suggests that optimal timing of treatment initiation may be an important determinant of post-treatment control of HIV.

Increasing the meaningful involvement of women in HIV cure-related research: a qualitative interview study in the United States

BACKGROUND

Cisgender women represent over half of people living with HIV globally. However, current research efforts toward a cure for HIV focus predominantly on cisgender men. The under-representation of women in HIV cure clinical studies is particularly problematic given data suggesting that sex-dependent phenotypes limit scientific discovery.

OBJECTIVE

We aimed to generate considerations to increase the meaningful involvement of women in HIV cure-related research.

MATERIALS AND METHODS

We conducted in-depth interviews with biomedical researchers and community members to better understand factors that could increase the meaningful involvement of women in HIV cure clinical trials. Participants were affiliated with academia, industry, community advisory boards, and community-based organizations, and were identified using listings from the AIDS Clinical Trials Group and the Martin Delaney Collaboratories. We used conventional content analysis to analyze the qualitative data.

RESULTS

We recruited 27 participants, of whom 11 were biomedical researchers and 16 were community members. Participants included 25 cisgender women, 1 transgender woman, and 1 cisgender man. Key considerations emerged, including the need to ensure that HIV cure studies reflect HIV epidemiologic trends and having accurate representation by sex and gender in HIV cure research. To increase the meaningful involvement of women, recommendations included instituting intentional enrollment goals, frequent and mandatory reporting on enrollment, and incentives for sites to enroll women. Additional themes included the need for agency and self-determination, attention to lived experiences, trauma and healing, and adequate support for women (e.g. logistical, psychosocial, mental, emotional, and physical). Participants noted that women would be willing to participate in HIV cure trials, related procedures (e.g. biopsies), and analytical treatment interruptions. They also expressed a desired for women-centered and holistic clinical trial designs that account for intersectionality.

CONCLUSIONS

Our empirical inquiry extends recent calls to action to increase diversity of people involved in HIV cure research. Redressing the under-inclusion of women in HIV cure research is an urgent imperative. The entire field must mobilize and reform to achieve this goal. Meaningfully involving women across the gender spectrum in HIV cure research is needed to ensure that interventions are safe, effective, scalable, and acceptable for all people with HIV.

Smoothed simulated pseudo-maximum likelihood estimation for nonlinear mixed effects models with censored responses

Nonlinear mixed effects models have been widely applied to analyses of data that arise from biological, agricultural, and environmental sciences. Estimation of and inference on parameters in nonlinear mixed effects models are often based on the specification of a likelihood function. Maximizing this likelihood function can be complicated by the specification of the random effects distribution, especially in the presence of multiple random effects. The implementation of nonlinear mixed effects models can be further complicated by left-censored responses, representing measurements from bioassays where the exact quantification below a certain threshold is not possible. Motivated by the need to characterize the nonlinear human immunodeficiency virus RNA viral load trajectories after the interruption of antiretroviral therapy, we propose a smoothed simulated pseudo-maximum likelihood estimation approach to fit nonlinear mixed effects models in the presence of left-censored observations. We establish the consistency and asymptotic normality of the resulting estimators. We develop testing procedures for the correlation among random effects and for testing the distributional assumptions on random effects against a specific alternative. In contrast to the existing variants of expectation-maximization approaches, the proposed methods offer flexibility in the specification of the random effects distribution and convenience in making inference about higher-order correlation parameters. We evaluate the finite-sample performance of the proposed methods through extensive simulation studies and illustrate them on a combined dataset from six AIDS Clinical Trials Group treatment interruption studies.

'With this study, we have hope that something is coming': community members' perceptions of HIV cure-related research in Durban, South Africa - a qualitative focus group study

BACKGROUND

Developing a cure for HIV remains a global scientific priority. In 2022, the Females Rising through Education, Support and Health (FRESH) cohort launched an HIV cure-related trial involving an analytical treatment interruption (ATI) in Durban, South Africa.

OBJECTIVES

To explore community perspectives about HIV cure-related research.

METHODS

Between July-August 2022, we conducted three focus groups with community members. We transcribed audio recordings verbatim and used content analysis to analyze the data.

RESULTS

Twenty community members (13 women and 7 men) participated in three focus groups (HIV status not included). Participants viewed HIV cure-related research as a way to address the issue of defaulting on (not taking) HIV treatment. Participants expressed hesitancy around ATIs, since these contradict longstanding treatment adherence messages. Participants shared concerns around the risk of side effects from experimental interventions balanced against potential efficacy. They advocated for trial participants to have the right to decide whether to inform their sex partners about their HIV status and ATI participation, rather than research teams making disclosure mandatory. Focus group participants also emphasized the importance of using simple language to explain HIV cure-related research.

CONCLUSIONS

With HIV cure trials set to launch across Africa in the future, there is a critical need to better understand and respond to local community needs and preferences and to adopt this as standard practice prior to regional trial implementation.

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.

Community engagement group model in basic and biomedical research: lessons learned from the BEAT-HIV Delaney Collaboratory towards an HIV-1 cure

INTRODUCTION

Achieving effective community engagement has been an objective of U.S. National Institutes of Health-funded HIV research efforts, including participation of persons with HIV. Community Advisory Boards (CABs) have remained the predominant model for community engagement since their creation in 1989. As HIV cure-directed research efforts have grown into larger academic-industry partnerships directing resources toward both basic and clinical research under the Martin Delaney Collaboratories (MDC), community input models have also evolved. The BEAT-HIV MDC Collaboratory, based at The Wistar Institute in Philadelphia, United States, implemented a three-part model for community engagement that has shown success in providing greater impact for community engagement across basic, biomedical, and social sciences research efforts.

DISCUSSION

In this paper, we review the case study of the formation of the BEAT-HIV Community Engagement Group (CEG) model, starting with the historical partnership between The Wistar Institute as a basic research center and Philadelphia FIGHT as a not-for-profit community-based organization (CBO), and culminating with the growth of community engagement under the BEAT-HIV MDC. Second, we present the impact of a cooperative structure including a Community Advisory Board (CAB), CBO, and researchers through the BEAT-HIV CEG model, and highlight collaborative projects that demonstrate the potential strengths, challenges, and opportunities of this model. We also describe challenges and future opportunities for the use of the CEG model.

CONCLUSIONS

Our CEG model integrating a CBO, CAB and scientists could help move us towards the goal of effective, equitable and ethical engagement in HIV cure-directed research. In sharing our lessons learned, challenges and growing pains, we contribute to the science of community engagement into biomedical research efforts with an emphasis on HIV cure-directed research. Our documented experience with implementing the CEG supports greater discussion and independent implementation efforts for this model to engage communities into working teams in a way we find a meaningful, ethical, and sustainable model in support of basic, clinical/biomedical, social sciences and ethics research.

HIV remission trial investigators' attitudes towards risk and risk mitigation in trials that include treatment interruption

Early-phase HIV remission ("cure") trials aim to test interventions developed to eradicate HIV or to sustainably control HIV without antiretroviral treatment (ART). Many remission trials include analytic treatment interruption (ATI) to evaluate interventions, which increases the risk to participants and their sexual partners. We conducted an online questionnaire of international HIV remission trial investigators and other study team members to assess their expectations regarding the time to achieve long-term control of HIV replication without treatment (functional cure) or complete eradication of replication-competent HIV virus (sterilizing cure); attitudes toward HIV remission research and the feasibility, acceptability, and efficacy of six HIV transmission risk mitigation strategies during trials with ATI of fixed duration. Nearly half of respondents (47%) reported expecting a functional cure for HIV to be achieved in 5-10 years, and one-third (35%) reported 10-20 years for a sterilizing cure to be achieved. On a scale of -3 to 3, mean scores indicated greater respondent concern about the risk of HIV transmission to partners during ATI (Time to rebound Mean: 0.4 and Fixed duration Mean: 11), compared to participant health risks from ATI (Time to Rebound Mean: -.9 and Fixed duration Mean: 0.0). With regard to feasibility, acceptability, and efficacy respectively, mitigation efforts rated positively included: requiring counseling for potential participants (Means: 2.3; 2.1; and 1.1), providing partner referrals for PrEP (Means: 1.3; 1.3; 1.5), providing pre-exposure proxylaxis directly to partners (Means: 1.0; 1.5; 1.6), and monitoring participants for new sexually transmitted disease acquisition (Means: 1.9; 1.4; 1.0). Respondents were less positive about requiring that participants' sexual partner(s) participate in risk counseling or limiting participation to those who commit to abstaining from sex during the entire ATI period. Our study demonstrates that HIV remission trial investigators and study team members are concerned about the risk of transmission to sexual partners during ATI. Separating the assessment of risk mitigation strategies for transmission risk into feasibility, acceptability, and efficacy allows the discovery of strategies that may best achieve all three outcomes. Additional research is needed to compare these more fine-grained assessments with views held by other investigators, people living with HIV, and trial participants.

Healthcare Provider Perspectives on HIV Cure Research in Ghana

Introduction

Antiretroviral therapy (ART) has reduced mortality and improved life expectancy among HIV patients but does not provide a cure. Patients must remain on lifelong medications and deal with drug resistance and side effects. This underscores the need for HIV cure research. However, participation in HIV cure research has risks without guaranteed benefits. We determined what HIV healthcare providers know about HIV cure research trials, the risks involved, and what kind of cure interventions they are likely to recommend for their patients.

Methods

We conducted in-depth qualitative interviews with 39 HIV care providers consisting of 12 physicians, 8 counsellors, 14 nurses, 2 pharmacists, 2 laboratory scientists, and 1 community advocate from three hospitals. Interviews were transcribed verbatim and coded, and thematic analysis was performed independently by two investigators.

Results

Participants were happy about the success of current treatments and hopeful that an HIV cure will be found in the near future, just as ART was discovered through research. They described cure as total eradication of the virus from the body and inability to test positive for HIV or transmit the virus. In terms of risk tolerance, respondents would recommend to their patients' studies with mild to moderate risks like what patients on antiretroviral therapy experience. Participants were reluctant to recommend treatment interruption to patients as part of a cure study and wished trials could be performed without stopping treatment. Healthcare providers categorically rejected death or permanent disability as an acceptable risk. The possibility of finding a cure that will benefit the individual or future generations was strong motivations for providers to recommend cure trials to their patients, as was transparency and adequate information on proposed trials. Overall, the participants were not actively seeking knowledge on cure research and lacked information on the various cure modalities under investigation.

Conclusion

While hopeful for an HIV cure, healthcare providers in Ghana expect a cure to be definitive and pose minimal risk to their patients.

HIV cure: an acceptability scientific agenda

PURPOSE OF REVIEW

Recent years have seen major investments into HIV cure research, seeking a permanent cure or remission. The purpose of this review is to consider how this important research agenda could be broadened to include issues of acceptability and appropriateness for different populations.

RECENT FINDINGS

We discuss how the definitions of cure such as functional cure (remission) or complete cure (viral elimination) could be interpreted differently by various populations. We also discuss the different methods of cure and the importance of including Africa in cure research to ensure that emerging remedies could be trialled and utilized on the continent that bears the brunt of the AIDS pandemic.

SUMMARY

We propose that the social science research of HIV cure acceptability should be done concurrently with the basic and clinical sciences, to ensure that cure methods consider stakeholder preferences.

Safety, immunogenicity and effect on viral rebound of HTI vaccines in early treated HIV-1 infection: a randomized, placebo-controlled phase 1 trial

HIVACAT T-cell immunogen (HTI) is a novel human immunodeficiency virus (HIV) vaccine immunogen designed to elicit cellular immune responses to HIV targets associated with viral control in humans. The AELIX-002 trial was a randomized, placebo-controlled trial to evaluate as a primary objective the safety of a combination of DNA.HTI (D), MVA.HTI (M) and ChAdOx1.HTI (C) vaccines in 45 early-antiretroviral (ART)-treated individuals (44 men, 1 woman; NCT03204617). Secondary objectives included T-cell immunogenicity, the effect on viral rebound and the safety of an antiretroviral treatment interruption (ATI). Adverse events were mostly mild and transient. No related serious adverse events were observed. We show here that HTI vaccines were able to induce strong, polyfunctional and broad CD4 and CD8 T-cell responses. All participants experienced detectable viral rebound during ATI, and resumed ART when plasma HIV-1 viral load reached either >100,000 copies ml^-1, >10,000 copies ml^-1 for eight consecutive weeks, or after 24 weeks of ATI. In post-hoc analyses, HTI vaccines were associated with a prolonged time off ART in vaccinees without beneficial HLA (human leukocyte antigen) class I alleles. Plasma viral load at the end of ATI and time off ART positively correlated with vaccine-induced HTI-specific T-cell responses at ART cessation. Despite limited efficacy of the vaccines in preventing viral rebound, their ability to elicit robust T-cell responses towards HTI may be beneficial in combination cure strategies, which are currently being tested in clinical trials.

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.

Challenges of HIV therapeutic vaccines clinical trials design

PURPOSE OF THE REVIEW

To discuss main challenges of therapeutic vaccine clinical trials design, implementation and analyses in the HIV cure field.

RECENT FINDINGS

Therapeutic vaccines are progressively being postulated as T-cell stimulating agents to use in combination HIV cure strategies, with the addition of immunomodulators, latency reversing agents and/or broadly neutralizing antibodies. Although promising strategies are rapidly evolving in preclinical studies using nonhuman primate models, translation into human testing in randomized controlled clinical trials is more challenging and expensive to conduct. Adaptive designs, access to cohorts of early-treated individuals, consensus on how to safely conduct analytical treatment interruptions, use of alternative statistical methods, development of point-of-care/home-based testing technologies and ensuring early engagement of communities where research is being developed are some of the critical aspects to consider to facilitate clinical trial development in the HIV cure field.

SUMMARY

Design and development of HIV therapeutic vaccine clinical trials poses many challenges, from Phase 0/pilot studies to Phase I/II trials in which efficacy of the intervention is being tested and antiretroviral therapy cessation is needed, complexity of cure trials progressively increases. Understanding fundamental issues and careful planning of therapeutic vaccine clinical trials is crucial to minimize design flaws, reduce loss of follow-ups and missing data while ensuring participant's safety and guarantee valid and accurate analyses and thus, better contribute towards an HIV cure.

Early intervention with 3BNC117 and romidepsin at antiretroviral treatment initiation in people with HIV-1: a phase 1b/2a, randomized trial

Attempts to reduce the human immunodeficiency virus type 1 (HIV-1) reservoir and induce antiretroviral therapy (ART)-free virologic control have largely been unsuccessful. In this phase 1b/2a, open-label, randomized controlled trial using a four-group factorial design, we investigated whether early intervention in newly diagnosed people with HIV-1 with a monoclonal anti-HIV-1 antibody with a CD4-binding site, 3BNC117, followed by a histone deacetylase inhibitor, romidepsin, shortly after ART initiation altered the course of HIV-1 infection ( NCT03041012 ). The trial was undertaken in five hospitals in Denmark and two hospitals in the United Kingdom. The coprimary endpoints were analysis of initial virus decay kinetics and changes in the frequency of CD4+ T cells containing intact HIV-1 provirus from baseline to day 365. Secondary endpoints included changes in the frequency of infected CD4+ T cells and virus-specific CD8+ T cell immunity from baseline to day 365, pre-ART plasma HIV-1 3BNC117 sensitivity, safety and tolerability, and time to loss of virologic control during a 12-week analytical ART interruption that started at day 400. In 55 newly diagnosed people (5 females and 50 males) with HIV-1 who received random allocation treatment, we found that early 3BNC117 treatment with or without romidepsin enhanced plasma HIV-1 RNA decay rates compared to ART only. Furthermore, 3BNC117 treatment accelerated clearance of infected cells compared to ART only. All groups had significant reductions in the frequency of CD4+ T cells containing intact HIV-1 provirus. At day 365, early 3BNC117 + romidepsin was associated with enhanced HIV-1 Gag-specific CD8+ T cell immunity compared to ART only. The observed virological and immunological effects of 3BNC117 were most pronounced in individuals whose pre-ART plasma HIV-1 envelope sequences were antibody sensitive. The results were not disaggregated by sex. Adverse events were mild to moderate and similar between the groups. During a 12-week analytical ART interruption among 20 participants, 3BNC117-treated individuals harboring sensitive viruses were significantly more likely to maintain ART-free virologic control than other participants. We conclude that 3BNC117 at ART initiation enhanced elimination of plasma viruses and infected cells, enhanced HIV-1-specific CD8+ immunity and was associated with sustained ART-free virologic control among persons with 3BNC117-sensitive virus. These findings strongly support interventions administered at the time of ART initiation as a strategy to limit long-term HIV-1 persistence.

HIV T-cell immunogen design and delivery

PURPOSE OF THE REVIEW

Not all T-cell responses against HIV are created equally and responses of certain epitope specificities have been associated with superior control of infection. These insights have spurred the development of a wide range of immunogen sequences, each with particular advantages and limitations.

RECENT FINDINGS

We review some of the most advanced designs that have reached or are close to reaching human clinical trials, with a special focus on T-cell immunogen developed for therapeutic use. We also touch upon the importance of how immunogens are delivered and point out the lamentable fact that there is essentially no alignment between different designs and vaccine regimens, which is a major hindrance to accelerated advances in the field.

SUMMARY

The design of an immunogen able to induce T-cell responses of adequate specificity and functionality is subject of a wide range of preclinical and clinical studies. Few designs have shown promise to date, but emerging data highlight the critical contribution of specificity to effective antiviral activity in vivo .

Acute HIV-1 infection viremia associate with rebound upon treatment interruption

BACKGROUND

Analytic treatment interruption (ATI) studies evaluate strategies to potentially induce remission in people living with HIV-1 but are often limited in sample size. We combined data from four studies that tested three interventions (vorinostat/hydroxychloroquine/maraviroc before ATI, Ad26/MVA vaccination before ATI, and VRC01 antibody infusion during ATI).

METHODS

The statistical validity of combining data from these participants was evaluated. Eleven variables, including HIV-1 viral load at diagnosis, Fiebig stage, and CD4+ T cell count were evaluated using pairwise correlations, statistical tests, and Cox survival models.

FINDINGS

Participants had homogeneous demographic and clinical characteristics. Because an antiviral effect was seen in participants who received VRC01 infusion post-ATI, these participants were excluded from the analysis, permitting a pooled analysis of 53 participants. Time to viral rebound was significantly associated with variables measured at the beginning of infection: pre-antiretroviral therapy (ART) viral load (HR = 1.34, p = 0.022), time to viral suppression post-ART initiation (HR = 1.07, p < 0.001), and area under the viral load curve (HR = 1.34, p = 0.026).

CONCLUSIONS

We show that higher viral loads in acute HIV-1 infection were associated with faster viral rebound, demonstrating that the initial stage of HIV-1 infection before ART initiation has a strong impact on viral rebound post-ATI years later.

FUNDING

This work was supported by a cooperative agreement between the Henry M. Jackson Foundation for the Advancement of Military Medicine and the US Department of the Army (W81XWH-18-2-0040). This research was funded, in part, by the US National Institute of Allergy and Infectious Diseases (AAI20052001) and the I4C Martin Delaney Collaboratory (5UM1AI126603-05).

Imaging and biopsy of HIV-infected individuals undergoing analytic treatment interruption

Background

HIV persistence during antiretroviral therapy (ART) is the principal obstacle to cure. Lymphoid tissue is a compartment for HIV, but mechanisms of persistence during ART and viral rebound when ART is interrupted are inadequately understood. Metabolic activity in lymphoid tissue of patients on long-term ART is relatively low, and increases when ART is stopped. Increases in metabolic activity can be detected by ¹⁸F-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and may represent sites of HIV replication or immune activation in response to HIV replication.

Methods

FDG-PET imaging will be used to identify areas of high and low metabolic uptake in lymphoid tissue of individuals undergoing long-term ART. Baseline tissue samples will be collected. Participants will then be randomized 1:1 to continue or interrupt ART via analytic treatment interruption (ATI). Image-guided biopsy will be repeated 10 days after ATI initiation. After ART restart criteria are met, image-guided biopsy will be repeated once viral suppression is re-achieved. Participants who continued ART will have a second FDG-PET and biopsies 12–16 weeks after the first. Genetic characteristics of HIV populations in areas of high and low FDG uptake will be assesed. Optional assessments of non-lymphoid anatomic compartments may be performed to evaluate HIV populations in distinct anatomic compartments.

Anticipated results

We anticipate that PET standardized uptake values (SUV) will correlate with HIV viral RNA in biopsies of those regions and that lymph nodes with high SUV will have more viral RNA than those with low SUV within a patient. Individuals who undergo ATI are expected to have diverse viral populations upon viral rebound in lymphoid tissue. HIV populations in tissues may initially be phylogenetically diverse after ATI, with emergence of dominant viral species (clone) over time in plasma. Dominant viral species may represent the same HIV population seen before ATI.

Discussion

This study will allow us to explore utility of PET for identification of HIV infected cells and determine whether high FDG uptake respresents areas of HIV replication, immune activation or both. We will also characterize HIV infected cell populations in different anatomic locations. The protocol will represent a platform to investigate persistence and agents that may target HIV populations.

Study protocol registration

Identifier: NCT05419024.

"I know that I was a part of making a difference": Participant motivations for joining a cure-directed HIV trial with an analytical treatment interruption

Analytical treatment interruption (ATI), defined as a closely monitored clinical pause in antiretroviral therapy, is a core component of many HIV cure-directed clinical studies. ATIs may cause significant physical and psychosocial risks for people living with HIV and, as a result, integrating participant and community perspectives into clinical trial designs that include an ATI is crucial to ensuring a successful and person-centered trial. We conducted semi-structured interviews with participants enrolling in the BEAT-2 cure-directed trial (NCT03588715). Interviews elicited participant motivations and decision-making processes for trial participation as well as participants' perceptions of the ATI. Interviews were recorded, transcribed, and analyzed using a directed content analysis. Fourteen of 15 trial participants completed interviews. The majority were Black (79%) cisgender male (79%). Participants noted several significant motivating factors contributing to their desire to enroll in the HIV cure-directed clinical trial, the most prominent being a desire to find a cure for HIV and help others in the HIV community. HIV care teams were the most commonly identified resource for patients when making the decision to enroll in the trial, and family, friends, and romantic partners also played a significant role. Altruism was a primary motivation for participation, although participants also shared interest in learning about HIV science and research. Participants had a strong understanding of trial procedures and displayed significant trust in the study team to keep them informed and healthy during their participation. The ATI was a significant source of anxiety for participants. Their primary worry was that their prior antiretroviral treatment (ART) regimen would no longer be effective once they resumed ART. Despite these concerns, participants shared considerable excitement for continued participation in the trial and being a part of the search towards an HIV cure.

"I would absolutely need to know that my partner is still going to be protected": Perceptions of HIV Cure-Related Research among Diverse HIV Serodifferent Couples in the United States

Most HIV cure studies remain in the early stage of investigation and may carry clinical risks to the participants and, in some cases, their partners. Surprisingly little socio-behavioral research has investigated the perceptions of couples - including HIV serodifferent couples - around HIV cure research, including factors that would influence recruitment and retention in trials. We conducted a qualitative study to explore perceptions of diverse HIV serodifferent partners in the U.S. We recruited 10 diverse HIV serodifferent couples (20 participants). We found participants had learned to cope with the reality of HIV, including protections during sex, and ascribed both positive and negative meanings to an HIV cure. Partners expressed concern about other's health and potentially caring for a sick partner and emphasized the importance of safety when participating in an HIV cure trial. They identified the need for partner protection measures during analytical treatment interruptions (ATIs) as an ethical imperative. Participants recounted experiences of HIV stigma due to being in HIV serodifferent relationships and viewed ATIs as leading to a detectable viral load, which could limit sexual expression, complicate disclosure decision making, and worsen HIV-related stigma. Our study's main contribution is to inform efforts to meaningfully engage diverse HIV serodifferent partners in HIV cure research in the U.S. Our data suggest PWH make decisions to participate in research based on close ones in their life and underscore the critical importance of acknowledging relationship dynamics in decisions to participate in research.

Participant experiences using novel home-based blood collection device for viral load testing in the HIV cure trials with analytical treatment interruptions

Background: HIV cure-directed clinical trials using analytical treatment interruptions (ATIs) require participants to adhere to frequent monitoring visits for viral load tests. Novel viral load monitoring strategies are needed to decrease participant burden during ATIs.Objective: To examine acceptability of a novel home-based blood collection device for viral load testing in the context of two ongoing ATI trials in Philadelphia, PA, United States.Methods: From January 2021 to February 2022, participants completed three in-depth interviews via teleconference during their participation in an ATI: (1) within two weeks of enrollment in the device study, (2) approximately four weeks after beginning to use the device, and (3) within two weeks of the end of the ATI when ART was re-initiated. We used conventional content analysis to analyze the data.Results: We recruited 17 participants: 15 were cisgender males, 1 cisgender female, and 1 transgender woman. We observed an overall 87% success rate in drawing blood with the device from home collection and found overall high acceptance of the device. A mean of 91.5 devices per participant were used for home-based blood collection. Most PWH viewed the device as relatively convenient, painless, easy to use, and a simple solution to frequent blood draws. The main challenge encountered was the inability to completely fill up devices with blood in some cases. Most participants reported positive experiences with mailing blood samples and could see themselves using the device on a regular basis outside of ATIs.Conclusions: Our study showed participant valued the novel home-based peripheral blood collection for viral load testing in the context of ATI trials. More research will be necessary to optimize implementation of the device and to assess whether blood collected can reliably measure viral loads in the context of ATI trials.

Perceptions of Risks and Benefits of Participating in HIV Cure-Related Research Among Diverse Young Adults Living with HIV in the United States: Qualitative Research Findings

In the United States, young adults have the highest rates of new HIV infections, and are less likely to be aware of their infection, be engaged in care, or achieve HIV viral suppression. As biomedical HIV research increasingly focuses on achieving long-term suppression without antiretroviral therapy (ART) and finding an HIV cure, little is known about perceptions of young adults living with HIV (YLWH) regarding HIV cure research. We recruited a diverse sample of 20 YLWH (18-29 years old) to participate in individual semistructured qualitative interviews to explore knowledge and perceptions of HIV cure research, and motivations and barriers to participation. Most participants had little knowledge of HIV cure research. Motivators of HIV cure research participation included altruism, stigma reduction, and the elimination of the clinical burdens of HIV. Barriers included potential physical side effects, psychological distress, the possibility of disclosure as a result of participating, and the amount of time required to participate. Most participants had concerns about analytic treatment interruptions (i.e., ART interruption to assess HIV remission), and indicated that they would want more frequent laboratory testing and protection for their sex partners during this time. Finally, participants suggested that, if other YLWH are considering participation in cure research, they should first learn as much as possible about the research, and then consider the potential personal benefits and the contribution that they could make to science and their communities. As HIV cure research advances, the participation of YLWH will be critical. Our study provides knowledge about how YLWH view HIV cure research. More sociobehavioral research is needed to ensure that those who are most likely to be the decision-makers and beneficiaries of an HIV cure are included at all levels of research.

The ethical case for placebo control in HIV-cure-related studies with ART interruption

Many studies that seek to cure HIV must ask participants to interrupt their antiretroviral treatment. In such circumstances, is it permissible to include a placebo group in the study? We explain why doing so is a scientific and an ethical necessity, and more benign than imagined.

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.

Community HIV clinicians' perceptions about HIV cure-related research in the Northwestern United States

Background: Research on stakeholder perspectives of HIV cure research has involved people with HIV (PWH), who generally cite the importance of HIV clinician advice in making decisions about trial participation. However, there has been little exploration of non-researcher community HIV clinician perspectives, which are clearly critical to the success of HIV cure-related research.Objective: We aimed to learn how community HIV clinicians perceive HIV cure research and identify factors that would lead them to support or discourage HIV cure trial participation by their patients.Methods: We recruited a purposive sample of 12 community HIV clinicians in metro-Seattle, WA to participate in structured interviews. We completed 11 interviews via teleconference and received one written response. We used conventional content analysis to analyze the data.Results: Overall, community HIV clinicians were supportive of patient participation in HIV cure trials. Factors affecting support included knowledge of local trials, ease of referral, patient immune function and health stability, study risks and benefits, burden of study requirements, patient characteristics, patient life stability, potential impact on engagement in care, study communication plans, and beliefs that patients should have the autonomy to decide to participate. Participants had concerns about trials requiring treatment delays or interruptions and HIV transmission risk. While their knowledge of the field was limited, they were interested in learning more about open HIV cure trials.Conclusions: It would benefit the HIV cure research community if those leading HIV cure trials make stronger efforts to engage community clinicians who care for PWH, but are not active researchers, early in the trial design process. Such engagement prior to launching HIV cure trials will improve trial designs, leading to better enrollment and retention within these important studies.

"It comes altogether as one:" perceptions of analytical treatment interruptions and partner protections among racial, ethnic, sex and gender diverse HIV serodifferent couples in the United States

BACKGROUND

Most HIV cure-related studies involve interrupting antiretroviral treatment to assess the efficacy of pharmacologic interventions - also known as analytical treatment interruptions (ATIs). ATIs imply the risk of passing HIV to sexual partners due to the loss of undetectable HIV status. There has been a notable lack of attention paid to perceptions of ATIs among racial, ethnic, sex and gender minorities, and HIV serodifferent couples. These populations are among those most impacted by HIV in the United States. Future HIV cure research paradigms should equitably include considerations from these groups.

METHODS

From August - October 2020, we conducted in-depth interviews with 10 racial, ethnic, sex, and gender minority HIV serodifferent couples in geographically diverse regions of the United States to understand their perspectives about ATIs and partner protection measures to prevent secondary HIV transmissions because of participation in ATI studies. We used framework analysis to analyze the qualitative data.

RESULTS

Of the 10 couples recruited, four identified as a gay couple, two as a gay and bisexual couple, two as a heterosexual couple, one as a gay and queer couple, and one as a queer couple. We found that HIV serodifferent couples in our study viewed ATIs as contradicting HIV treatment adherence messages. Couples expressed discomfort around ATIs in HIV cure research. They were concerned with the return of HIV detectability and worried ATIs might result in secondary HIV transmission. Participants were strongly in favor of using a range of partner protection measures during ATIs that included PrEP, HIV risk reduction counseling, and alternatives for penetrative sex practices. Couples also recommended that sex partners be consulted or involved as part of ATI trials.

CONCLUSIONS

Our findings highlight new potential opportunities and strategies to mitigate risk of HIV transmission during ATIs among key groups historically under-represented in HIV cure research. Findings also underscore the relational aspects of ATI trials. We provide preliminary considerations for planning ATI trials with diverse HIV serodifferent partners. Future studies should continue to explore these issues among other types of partnerships, cultures, and socio-cultural settings.

Insights into the HIV-1 Latent Reservoir and Strategies to Cure HIV-1 Infection

Since the first discovery of human immunodeficiency virus 1 (HIV-1) in 1983, the targeted treatment, antiretroviral therapy (ART), has effectively limited the detected plasma viremia below a very low level and the technique has been improved rapidly. However, due to the persistence of the latent reservoir of replication-competent HIV-1 in patients treated with ART, a sudden withdrawal of the drug inevitably results in HIV viral rebound and HIV progression. Therefore, more understanding of the HIV-1 latent reservoir (LR) is the priority before developing a cure that thoroughly eliminates the reservoir. HIV-1 spreads through both the release of cell-free particles and by cell-to-cell transmission. Mounting evidence indicates that cell-to-cell transmission is more efficient than cell-free transmission of particles and likely influences the pathogenesis of HIV-1 infection. This mode of viral transmission also influences the generation and maintenance of the latent reservoir, which represents the main obstacle for curing the infection. In this review, the definition, establishment, and maintenance of the HIV-1 LR, along with the state-of-the-art quantitative approaches that directly quantify HIV-1 intact proviruses, are elucidated. Strategies to cure HIV infection are highlighted. This review will renew hope for a better and more thorough cure of HIV infection for mankind and encourage more clinical trials to achieve ART-free HIV remission.

Viral and Host Biomarkers of HIV Remission Post Treatment Interruption

PURPOSE OF REVIEW

HIV rebound/remission after antiretroviral therapy (ART) interruption is likely influenced by (a) the size of the inducible replication-competent HIV reservoir and (b) factors in the host environment that influence immunological pressures on this reservoir. Identifying viral and/or host biomarkers of HIV rebound after ART cessation may improve the safety of treatment interruptions and our understanding of how the viral-host interplay results in post-treatment control. Here we review the predictive and functional significance of recently suggested viral and host biomarkers of time to viral rebound and post-treatment control following ART interruption.

RECENT FINDINGS

There are currently no validated viral or host biomarkers of viral rebound; however, several biomarkers have been recently suggested. A combination of viral and host factors will likely be needed to predict viral rebound and to better understand the mechanisms contributing to post-treatment control of HIV, critical steps to developing a cure for HIV infection.

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

The AIDS Clinical Trials Group A5345 study (NCT03001128) included an intensively monitored antiretroviral pause (IMAP), during which participants living with HIV temporarily stopped antiretroviral treatment (ART) in an effort to identify biomarkers that could predict HIV rebound. We evaluated the potential impact of the IMAP on A5345 study participants in the United States by questioning them immediately after the IMAP and at the end of the study. We administered longitudinal sociobehavioral questionnaires to participants following the IMAP when they resumed ART and at the end of the study. We summarized descriptive data from the post-IMAP and end-of-study questionnaires. Open-ended responses were analyzed using conventional content analysis. Reactions to pausing ART involved a mixture of curiosity and satisfaction from contributing to science. All participants indicated adherence with the ART interruption. About half (9/17) of post-IMAP questionnaire respondents reported having sexual partner(s) during the IMAP, and of those, nearly all (8/9) did not find it difficult to use measures to prevent HIV transmission to partners. The majority believed that they benefited from the study, yet some had elevated anxiety following the IMAP and at the end of the study. Most (24/29) respondents who completed the end-of-study questionnaire would recommend the study to other people living with HIV. Our findings underscore the relevance of the psychosocial aspects of participating in studies that involve interruptions of ART. Understanding how participants experience this research is invaluable for informing the design of future research aimed at sustained ART-free virologic suppression.

Genome-scale metabolic models for natural and long-term drug-induced viral control in HIV infection

A system-level up-regulation of OXPHOS and glycolysis could play a role in latent reservoir dynamics and immunosenescence in HIV-1–infected individuals with long-term successful therapy.

Genome-scale metabolic models (GSMMs) can provide novel insights into metabolic reprogramming during disease progression and therapeutic interventions. We developed a context-specific system-level GSMM of people living with HIV (PLWH) using global RNA sequencing data from PBMCs with suppressive viremia either by natural (elite controllers, PLWH_EC) or drug-induced (PLWH_ART) control. This GSMM was compared with HIV-negative controls (HC) to provide a comprehensive systems-level metabo-transcriptomic characterization. Transcriptomic analysis identified up-regulation of oxidative phosphorylation as a characteristic of PLWH_ART, differentiating them from PLWH_EC with dysregulated complexes I, III, and IV. The flux balance analysis identified altered flux in several intermediates of glycolysis including pyruvate, α-ketoglutarate, and glutamate, among others, in PLWH_ART. The in vitro pharmacological inhibition of OXPHOS complexes in a latent lymphocytic cell model (J-Lat 10.6) suggested a role for complex IV in latency reversal and immunosenescence. Furthermore, inhibition of complexes I/III/IV induced apoptosis, collectively indicating their contribution to reservoir dynamics.

Attitudes About Analytic Treatment Interruption (ATI) in HIV Remission Trials with Different Antiretroviral Therapy (ART) Resumption Criteria

HIV remission trials often require temporary stopping of antiretroviral therapy (ART)-an approach called analytic treatment interruption (ATI). Trial designs resulting in viremia raise risks for participants and sexual partners. We conducted a survey on attitudes about remission trials, comparing ART resumption criteria (lower-risk "time to rebound" and higher-risk "sustained viremia") among participants from an acute HIV cohort in Thailand. Analyses included Wilcoxon-Ranks and multivariate logistic analysis. Most of 408 respondents supported ATI trials, with slightly higher approval of, and willingness to participate in, trials using time to rebound versus sustained viremia criteria. Less than half of respondents anticipated disclosing trial participation to partners and over half indicated uncertainty or unwillingness about whether partners would be willing to use PrEP. Willingness to participate was higher among those who rated higher trial approval, lower anticipated burden, and those expecting to make the decision independently. Our findings support acceptability of ATI trials among most respondents. Participant attitudes and anticipated behaviors, especially related to transmission risk, have implications for future trial design and informed consent.

Gut microbiome signatures linked to HIV-1 reservoir size and viremia control

BACKGROUND

The potential role of the gut microbiome as a predictor of immune-mediated HIV-1 control in the absence of antiretroviral therapy (ART) is still unknown. In the BCN02 clinical trial, which combined the MVA.HIVconsv immunogen with the latency-reversing agent romidepsin in early-ART treated HIV-1 infected individuals, 23% (3/13) of participants showed sustained low-levels of plasma viremia during 32 weeks of a monitored ART pause (MAP). Here, we present a multi-omics analysis to identify compositional and functional gut microbiome patterns associated with HIV-1 control in the BCN02 trial.

RESULTS

Viremic controllers during the MAP (controllers) exhibited higher Bacteroidales/Clostridiales ratio and lower microbial gene richness before vaccination and throughout the study intervention when compared to non-controllers. Longitudinal assessment indicated that the gut microbiome of controllers was enriched in pro-inflammatory bacteria and depleted in butyrate-producing bacteria and methanogenic archaea. Functional profiling also showed that metabolic pathways related to fatty acid and lipid biosynthesis were significantly increased in controllers. Fecal metaproteome analyses confirmed that baseline functional differences were mainly driven by Clostridiales. Participants with high baseline Bacteroidales/Clostridiales ratio had increased pre-existing immune activation-related transcripts. The Bacteroidales/Clostridiales ratio as well as host immune-activation signatures inversely correlated with HIV-1 reservoir size.

CONCLUSIONS

The present proof-of-concept study suggests the Bacteroidales/Clostridiales ratio as a novel gut microbiome signature associated with HIV-1 reservoir size and immune-mediated viral control after ART interruption. Video abstract.

Ethical and practical considerations for cell and gene therapy toward an HIV cure: findings from a qualitative in-depth interview study in the United States

BACKGROUND

HIV cure research involving cell and gene therapy has intensified in recent years. There is a growing need to identify ethical standards and safeguards to ensure cell and gene therapy (CGT) HIV cure research remains valued and acceptable to as many stakeholders as possible as it advances on a global scale.

METHODS

To elicit preliminary ethical and practical considerations to guide CGT HIV cure research, we implemented a qualitative, in-depth interview study with three key stakeholder groups in the United States: (1) biomedical HIV cure researchers, (2) bioethicists, and (3) community stakeholders. Interviews permitted evaluation of informants' perspectives on how CGT HIV cure research should ethically occur, and were transcribed verbatim. We applied conventional content analysis focused on inductive reasoning to analyze the rich qualitative data and derive key ethical and practical considerations related to CGT towards an HIV cure.

RESULTS

We interviewed 13 biomedical researchers, 5 community members, and 1 bioethicist. Informants generated considerations related to: perceived benefits of CGT towards an HIV cure, perceived risks, considerations necessary to ensure an acceptable benefit/risk balance, CGT strategies considered unacceptable, additional ethical considerations, and considerations for first-in-human CGT HIV cure trials. Informants also proposed important safeguards to developing CGT approaches towards an HIV cure, such as the importance of mitigating off-target effects, mitigating risks associated with long-term duration of CGT interventions, and mitigating risks of immune overreactions.

CONCLUSION

Our study identified preliminary considerations for CGT-based HIV cure across three key stakeholder groups. Respondents identified an ideal cure strategy as one which would durably control HIV infection, protect the individual from re-acquisition, and eliminate transmission to others. Known and unknown risks should be anticipated and perceived as learning opportunities to preserve and honor the altruism of participants. Preclinical studies should support these considerations and be transparently reviewed by regulatory experts and peers prior to first-in-human studies. To protect the public trust in CGT HIV cure research, ethical and practical considerations should be periodically revisited and updated as the science continues to evolve. Additional ethics studies are required to expand stakeholder participation to include traditionally marginalized groups and clinical care providers.

The RIO trial: rationale, design, and the role of community involvement in a randomised placebo-controlled trial of antiretroviral therapy plus dual long-acting HIV-specific broadly neutralising antibodies (bNAbs) in participants diagnosed with recent HIV infection-study protocol for a two-stage randomised phase II trial

BACKGROUND

Antiretroviral therapy (ART) has led to dramatic improvements in survival for people living with HIV, but is unable to cure infection, or induce viral control off therapy. Designing intervention trials with novel agents with the potential to confer a period of HIV remission without ART remains a key scientific and community goal. We detail the rationale, design, and outcomes of a randomised, placebo-controlled trial of two HIV-specific long-acting broadly neutralising antibodies (bNAbs): 3BNC117-LS and 10-1074-LS, which target CD4 binding site and V3 loop respectively, on post-treatment viral control.

METHODS

RIO is a randomised, placebo-controlled, double-blinded prospective phase II study. Eligible individuals will have started ART within 3 months of primary HIV infection and have viral sequences that appear to be sensitive to both bNAbs. It will randomise 72 eligible participants 1:1 to the following arms via a two-stage design. In Stage 1, arm A participants are given dual long-acting (LS-variants) bNAbs infusions, followed by intensively monitored Analytical Treatment Interruption (ATI) (n = 36); in arm B, participants receive placebo infusions followed by ATI. The primary endpoint will be time to viral rebound within 36 weeks after ATI. Upon viral rebound, the participant and researcher are unblinded. Participants in arm A recommence ART and complete the study. Participants in arm B are invited to restart ART and enroll into Stage 2 where they will receive open-label LS bNAbs, followed by a second ATI 24 weeks after. Secondary and exploratory endpoints include adverse events, time to undetectable viraemia after restarting ART, immunological markers, HIV proviral DNA, serum bNAb concentrations in blood, bNAb resistance at viral rebound, and quality of life measures.

DISCUSSION

The two-stage design was determined in collaboration with community involvement. This design allows all participants the option to receive bNAbs. It also tests the hypothesis that bNAbs may drive sustained HIV control beyond the duration of detectable bNAb concentrations. Community representatives were involved at all stages. This included the two-stage design, discussion on the criteria to restart ART, frequency of monitoring visits off ART, and reducing the risk of onward transmission to HIV-negative partners. It also included responding to the challenges of COVID-19.

TRIAL REGISTRATION

The protocol is registered on Clinical.

TRIALS

gov and EudraCT and has approval from UK Ethics and MHRA.

Paradoxically greater persistence of HIV RNA+ cells in lymphoid tissue when ART is initiated in the earliest stage of infection

Starting antiretroviral therapy (ART) in Fiebig 1 acute HIV infection limits the size of viral reservoirs in lymphoid tissues, but does not impact time to virus rebound during a treatment interruption. To better understand why the reduced reservoir size did not increase the time to rebound we measured the frequency and location of HIV RNA⁺ cells in lymph nodes from participants in the RV254 acute infection cohort. HIV RNA⁺ cells were detected more frequently and in greater numbers when ART was initiated in Fiebig 1 compared to later Fiebig stages and were localized to the T-cell zone compared to the B-cell follicle with treatment in later Fiebig stages. Variability of virus production in people treated during acute infection suggests that the balance between virus-producing cells and the immune response to clear infected cells rapidly evolves during the earliest stages of infection.

Clinical Trials Registration: NCT02919306.

Preserved central nervous system functioning after use of romidepsin as a latency-reversing agent in an HIV cure strategy

OBJECTIVE

To assess the central nervous system (CNS) impact of a kick&kill HIV cure strategy using therapeutic vaccine MVA.HIVconsv and the histone deacetylase inhibitor (HDACi) romidepsin (RMD) as latency-reversing agent.

DESIGN

Neurological observational substudy of the BCN02 trial (NCT02616874), a proof-of-concept, open-label, single-arm, phase I clinical trial testing the safety and immunogenicity of the MVA.HIVconsv vaccine and RMD in early-treated HIV-1-infected individuals. A monitored antiretroviral pause (MAP) was performed, with cART resumption after 2 pVL more than 2000 copies/ml. Reinitiated participants were followed for 24 weeks.

METHODS

Substudy participation was offered to all BCN02 participants (N = 15). Evaluations covered cognitive, functional, and brain imaging outcomes, performed before RMD administration (pre-RMD), after three RMD infusions (post-RMD), and at the end of the study (EoS). A group of early-treated HIV-1-infected individuals with matched clinical characteristics was additionally recruited (n = 10). Primary endpoint was change in a global cognitive score (NPZ-6).

RESULTS

Eleven participants from BCN02 trial were enrolled. No significant changes were observed in cognitive, functional, or brain imaging outcomes from pre-RMD to post-RMD. No relevant alterations were detected from pre-RMD to EoS either. Scores at EoS were similar in participants off cART for 32 weeks (n = 3) and those who resumed therapy for 24 weeks (n = 7). Controls showed comparable punctuations in NPZ-6 across all timepoints.

CONCLUSION

No detrimental effects on cognitive status, functional outcomes, or brain imaging parameters were observed after using the HDACi RMD as latency-reversing agent with the MVA.HIVconsv vaccine in early-treated HIV-1-infected individuals. CNS safety was also confirmed after completion of the MAP.

Effect of 3BNC117 and romidepsin on the HIV-1 reservoir in people taking suppressive antiretroviral therapy (ROADMAP): a randomised, open-label, phase 2A trial

BACKGROUND

The administration of broadly neutralising anti-HIV-1 antibodies before latency reversal could facilitate elimination of HIV-1-infected CD4 T cells. We tested this concept by combining the broadly neutralising antibody 3BNC117 in combination with the latency-reversing agent romidepsin in people with HIV-1 who were taking suppressive antiretroviral therapy (ART).

METHODS

We did a randomised, open-label, phase 2A trial at three university hospital centres in Denmark, Germany, and the USA. Eligible participants were virologically suppressed adults aged 18-65 years who were infected with HIV-1 and on ART for at least 18 months, with plasma HIV-1 RNA concentrations of less than 50 copies per mL for at least 12 months, and a CD4 T-cell count of greater than 500 cells per μL. Participants were randomly assigned (1:1) to receive 3BNC117 plus romidepsin or romidepsin alone in two cycles. All participants received intravenous infusions of romidepsin (5 mg/m² given over 120 min) at weeks 0, 1, and 2 (treatment cycle 1) and weeks 8, 9, and 10 (treatment cycle 2). Those in the 3BNC117 plus romidepsin group received an intravenous infusion of 3BNC117 (30 mg/kg given over 60 min) 2 days before each treatment cycle. An analytic treatment interruption (ATI) of ART was done at week 24 in both groups. Our primary endpoint was time to viral rebound during analytic treatment interruption, which was assessed in all participants who completed both treatment cycles and ATI. We used a log-rank test to compare time to viral rebound during analytic treatment interruption between the two groups. This trial is registered with ClinicalTrials.gov, NCT02850016. It is closed to new participants, and all follow-up is complete.

FINDINGS

Between March 20, 2017, and Aug 14, 2018, 22 people were enrolled and randomly assigned, 11 to the 3BNC117 plus romidepsin group and 11 to the romidepsin group. 19 participants completed both treatment cycles and the ATI: 11 in the 3BNC117 plus romidepsin group and 8 in the romidepsin group. The median time to viral rebound during ATI was 18 days (IQR 14-28) in the 3BNC117 plus romidepsin group and 28 days (21-35) in the romidepsin group B (p=0·0016). Although this difference was significant, prolongation of time to viral rebound was not clinically meaningful in either group. All participants in both groups reported adverse events, but overall the combination of 3BNC117 and romidepsin was safe. Two severe adverse events were observed in the romidepsin group during 48 weeks of follow-up, one of which-increased direct bilirubin-was judged to be related to treatment.

INTERPRETATION

The combination of 3BNC117 and romidepsin was safe but did not delay viral rebound during analytic treatment interruptions in individuals on long-term ART. The results of our trial could serve as a benchmark for further optimisation of HIV-1 curative strategies among people with HIV-1 who are taking suppressive ART.

FUNDING

amfAR, German Center for Infection Research.

Preliminary Acceptability of a Home-Based Peripheral Blood Collection Device for Viral Load Testing in the Context of Analytical Treatment Interruptions in HIV Cure Trials: Results from a Nationwide Survey in the United States

Frequent viral load testing is necessary during analytical treatment interruptions (ATIs) in HIV cure-directed clinical trials, though such may be burdensome and inconvenient to trial participants. We implemented a national, cross-sectional survey in the United States to examine the acceptability of a novel home-based peripheral blood collection device for HIV viral load testing. Between June and August 2021, we distributed an online survey to people with HIV (PWH) and community members, biomedical HIV cure researchers and HIV care providers. We performed descriptive analyses to summarize the results. We received 73 survey responses, with 51 from community members, 12 from biomedical HIV cure researchers and 10 from HIV care providers. Of those, 51 (70%) were cisgender men and 50 (68%) reported living with HIV. Most (>80% overall) indicated that the device would be helpful during ATI trials and they would feel comfortable using it themselves or recommending it to their patients/participants. Of the 50 PWH, 42 (84%) indicated they would use the device if they were participating in an ATI trial and 27 (54%) also expressed a willingness to use the device outside of HIV cure studies. Increasing sensitivity of viral load tests and pluri-potency of the device (CD4 count, chemistries) would augment acceptability. Survey findings provide evidence that viral load home testing would be an important adjunct to ongoing HIV cure-directed trials involving ATIs. Survey findings may help inform successful implementation and uptake of the device in the context of personalized HIV care.

Immunotherapeutic approaches to HIV cure and remission

PURPOSE OF REVIEW

Despite improvements in the effectiveness of antiretroviral therapy (ART), there are still unmet needs for people living with HIV which drive the search for a cure for HIV infection. The goal of this review is to discuss the challenges and recent immunotherapeutic advances towards developing a safe, effective and durable cure strategy for HIV.

RECENT FINDINGS

In recent years, advances have been made in uncovering the mechanisms of persistence of latent HIV and in developing more accurate assays to measure the intact proviral reservoir. Broadly neutralising antibodies and modern techniques to enhance antibody responses have shown promising results. Other strategies including therapeutic vaccination, latency reversal agents, and immunomodulatory agents have shown limited success, but newer interventions including engineered T cells and other immunotherapies may be a potent and flexible strategy for achieving HIV cure.

SUMMARY

Although progress with newer cure strategies may be encouraging, challenges remain and it is essential to achieve a high threshold of safety and effectiveness in the era of safe and effective ART. It is likely that to achieve sustained HIV remission or cure, a multipronged approach involving a combination of enhancing both adaptive and innate immunity is required.

Nonlinear mixed-effects models for HIV viral load trajectories before and after antiretroviral therapy interruption, incorporating left censoring

OBJECTIVES

Characterizing features of the viral rebound trajectories and identifying host, virological, and immunological factors that are predictive of the viral rebound trajectories are central to HIV cure research. We investigate if key features of HIV viral decay and CD4 trajectories during antiretroviral therapy (ART) are associated with characteristics of HIV viral rebound following ART interruption.

METHODS

Nonlinear mixed effect (NLME) models are used to model viral load trajectories before and following ART interruption, incorporating left censoring due to lower detection limits of viral load assays. A stochastic approximation EM (SAEM) algorithm is used for parameter estimation and inference. To circumvent the computational intensity associated with maximizing the joint likelihood, we propose an easy-to-implement three-step method.

RESULTS

We evaluate the performance of the proposed method through simulation studies and apply it to data from the Zurich Primary HIV Infection Study. We find that some key features of viral load during ART (e.g., viral decay rate) are significantly associated with important characteristics of viral rebound following ART interruption (e.g., viral set point).

CONCLUSIONS

The proposed three-step method works well. We have shown that key features of viral decay during ART may be associated with important features of viral rebound following ART interruption.

OUP accepted manuscript

Background

Methods

Results

Conclusions

Ethical considerations for HIV remission clinical research involving participants diagnosed during acute HIV infection

HIV remission clinical researchers are increasingly seeking study participants who are diagnosed and treated during acute HIV infection—the brief period between infection and the point when the body creates detectable HIV antibodies. This earliest stage of infection is often marked by flu-like illness and may be an especially tumultuous period of confusion, guilt, anger, and uncertainty. Such experiences may present added ethical challenges for HIV research recruitment, participation, and retention. The purpose of this paper is to identify potential ethical challenges associated with involving acutely diagnosed people living with HIV in remission research and considerations for how to mitigate them. We identify three domains of potential ethical concern for clinicians, researchers, and ethics committee members to consider: 1) Recruitment and informed consent; (2) Transmission risks and partner protection; and (3) Ancillary and continuing care. We discuss each of these domains with the aim of inspiring further work to advance the ethical conduct of HIV remission research. For example, experiences of confusion and uncertainty regarding illness and diagnosis during acute HIV infection may complicate informed consent procedures in studies that seek to recruit directly after diagnosis. To address this, it may be appropriate to use staged re-consent procedures or comprehension assessment. Responsible conduct of research requires a broad understanding of acute HIV infection that encompasses its biomedical, psychological, social, and behavioral dimensions. We argue that the lived experience of acute HIV infection may introduce ethical concerns that researchers and reviewers should address during study design and ethical approval.