How to Address the Risk of HIV Transmission in Remission Studies With Treatment Interruption: The Low-Hanging Fruit Approach

Exploring the ethics of tuberculosis human challenge models

We extend recent conversation about the ethics of human challenge trials to tuberculosis (TB). TB challenge studies could accelerate vaccine development, but ethical concerns regarding risks to trial participants and third parties have been a limiting factor. We analyse the expected social value and risks of different challenge models, concluding that if a TB challenge trial has between a 10% and a 50% chance of leading to the authorisation and near-universal delivery of a more effective vaccine 3-5 years earlier, then the trial would save between 26 400 and 1 100 000 lives over the next 10 years. We also identify five important ethical considerations that differentiate TB from recent human challenge trials: an exceptionally high disease burden with no highly effective vaccine; heightened third party risk following the trial, and, partly for that reason, uniquely stringent biosafety requirements for the trial; risks associated with best available TB treatments; and difficulties with TB disease detection. We argue that there is good reason to consider conducting challenge trials with attenuated strains like Bacillus Calmette-Guérin or attenuated Mycobacterium tuberculosis.

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.

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.

"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 sociobehavioral 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 United States. 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 each 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 United States. Our data suggest people with HIV 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.

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.

"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.

Considerations for Increasing Racial, Ethnic, Gender, and Sexual Diversity in HIV Cure-Related Research with Analytical Treatment Interruptions: A Qualitative Inquiry

Despite disproportionate incidence and prevalence of HIV among transgender individuals, cisgender women, and racial and ethnic minority groups, all remain underrepresented in HIV cure research. As HIV cure trials are scaled up, there is emerging research on ways to mitigate risks of HIV acquisition for sexual partners of analytical treatment interruption (ATI) trial participants. As such, it is imperative that HIV cure researchers consider the implications of implementing ATIs in populations that are disproportionately affected by HIV, but largely underrepresented in trials to date. In this qualitative study, we sought to derive triangulated perspectives on the social and ethical implications regarding ATIs and partner protection strategies during ATIs among under-represented populations. We conducted 21 in-depth interviews with 5 types of informants: bioethicists, community members [people living with HIV (PLWH) and their advocates], biomedical HIV cure researchers, sociobehavioral scientists, and HIV care providers. We analyzed the data using conventional content analysis and reduced the data to important considerations for implementing ATI trials in diverse communities and settings. Our study revealed the following key themes: (1) attention must be paid to gender and power dynamics in ATI trials; (2) ATI trials should be designed and implemented through the lenses of intersectionality and equity frameworks; (3) ATI trials may have both positive and negative effects on stigma for PLWH and their partners; and (4) partnership dynamics should be considered when designing ATI protocols. Our study generated actionable considerations that could be implemented in ATI trials to promote their acceptability to communities that have been underrepresented in HIV cure research to date. Research teams must invest in robust community and stakeholder engagement to define best practices. Paying attention to representation and equity will also promote better and more equitable implementation of HIV cure strategies once these become ready for rollout.

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.

Ethical and practical considerations for mitigating risks to sexual partners during analytical treatment interruptions in HIV cure-related research

BACKGROUND

Background: Analytical treatment interruptions (ATIs) in HIV cure-related research can result in trial participants becoming viremic with HIV, placing HIV-negative sexual partners at elevated risk of acquiring HIV.

OBJECTIVE

Objective:Our study aimed to generate ethical and practical considerations for designing and implementing appropriate risk mitigation strategies to reduce unintended HIV transmission events during ATIs.

METHODS

Methods: We conducted 21 in-depth interviews with five types of informants: bioethicists, community members, biomedical HIV cure researchers, socio-behavioral scientists/epidemiologists, and HIV care providers. We used conventional content analysis to analyze the data and generate considerations.

RESULTS

Results: Key findings include: 1) Ethical permissibility of ATI trials depends on due diligence and informed consent to mitigate risks to participants and their sexual partners; 2) Participants should receive adequate support and/or counseling if they choose to disclose ATI participation to their partners; 3) Measures to protect sexual partners of trial participants from HIV transmission during ATIs should include referral to and/or provision of pre-exposure prophylaxis, as well as other available means of preventing HIV transmission; 4) There is uncertainty regarding the appropriate management of emerging sexually transmitted infections during ATI trials and possible protection measures for multiple and/or anonymous partners of ATI trial participants.

CONCLUSION

Conclusion: While there is no way to completely eliminate the risk of HIV transmission to sexual partners during ATIs, HIV cure trialists and sponsors should consider the ethical concerns related to the sexual partners of ATI participants. Doing so is essential to ensuring the welfare of participants, their partners and the trustworthiness of research.

Novel Approaches Towards a Functional Cure of HIV/AIDS

Therapeutic approaches towards a functional cure or eradication of HIV have gained renewed momentum upon encouraging data emerging from studies in SIV monkey models and recent results from human clinical studies. However, a multitude of questions remain to be addressed, including how to deal with the latent viral reservoir, how to boost the host immune response to the virus and what the hurdles are to reach relevant viral compartments in the body. Advances have been made especially with regard to identifying agents that can reactivate the latent virus in vivo and boost the cellular and humoral immunity, but it remains largely unclear whether any of these strategies can awaken a sufficiently large fraction of the viral reservoir and whether the boosted immunity can prevent rapid viral replication once antiretroviral treatments are stopped.

A collaborative, multidisciplinary approach to HIV transmission risk mitigation during analytic treatment interruption

Analytic treatment interruptions (ATIs) are currently the standard for assessing the impact of experimental interventions aimed at inducing sustained antiretroviral therapy (ART)-free remission in trials related to HIV cure. ATIs are associated with substantial risk to both study participants and their sexual partner(s). Two documented HIV transmissions occurring in the context of ATIs have been recently reported, but recommendations for mitigating the risk of such events during ATIs are limited. We outline a practical approach to risk mitigation during ATI studies and describe strategies we are utilising in an upcoming clinical trial that may be applicable to other centres.