Introduction

Distinct biological factors exist that affect the natural history of HIV and the host immune response between women and men. These differences must be addressed to permit the optimal design of effective HIV eradication strategies for much of the HIV-positive population.

Methods and results

Here, we review the literature on sex-based differences in HIV pathogenesis and natural history in tissues and anatomic compartments, HIV latency and transcriptional activity, and host immunity including the role of sex hormones. We then outline the potential effects of these differences on HIV persistence, and on the safety and efficacy of HIV eradication and curative interventions. Finally, we discuss the next steps necessary to elucidate these factors to achieve a cure for HIV, taking in account the complex ethical issues and the regulatory landscape in the hopes of stimulating further research and awareness in these areas.

Conclusions

Targeted enrollment of women in clinical trials and careful sex-based analysis will be crucial to gain further insights into sex-based differences in HIV persistence and to design sex-specific approaches to HIV eradication, if required.

Introduction

Distinct biological factors exist that affect the natural history of HIV and the host immune response between women and men. These differences must be addressed to permit the optimal design of effective HIV eradication strategies for much of the HIV-positive population.

Methods and results

Here, we review the literature on sex-based differences in HIV pathogenesis and natural history in tissues and anatomic compartments, HIV latency and transcriptional activity, and host immunity including the role of sex hormones. We then outline the potential effects of these differences on HIV persistence, and on the safety and efficacy of HIV eradication and curative interventions. Finally, we discuss the next steps necessary to elucidate these factors to achieve a cure for HIV, taking in account the complex ethical issues and the regulatory landscape in the hopes of stimulating further research and awareness in these areas.

Conclusions

Targeted enrollment of women in clinical trials and careful sex-based analysis will be crucial to gain further insights into sex-based differences in HIV persistence and to design sex-specific approaches to HIV eradication, if required.

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

There are two concurrent and novel major research pathways toward strategies for HIV control: (1) long-acting antiretroviral therapy (ART) formulations and (2) research aimed at conferring sustained ART-free HIV remission, considered a step toward an HIV cure. The importance of perspectives from people living with HIV on the development of new modalities is high, but data are lacking. We administered an online survey in which respondents selected their likelihood of participation or nonparticipation in HIV cure/remission research based on potential risks and perceived benefits of these new modalities. We also tested the correlation between perceptions of potential risks and benefits with preferences of virologic control strategies and/or responses to scenario choices, while controlling for respondent characteristics. Of the 282 eligible respondents, 42% would be willing to switch from oral daily ART to long-acting ART injectables or implantables taken at 6-month intervals, and 24% to a hypothetical ART-free remission strategy. We found statistically significant gender differences in perceptions of risk and preferences of HIV control strategies, and possible psychosocial factors that could mediate willingness to switch to novel HIV treatment or remission options. Our study yielded data on possible desirable product characteristics for future HIV treatment and remission options. Findings also revealed differences in motivations and preferences across gender and other sociodemographic characteristics that may be actionable as part of research recruitment efforts. The diversity of participant perspectives reveals the need to provide a variety of therapeutic options to people living with HIV and to acknowledge their diverse experiential expertise when developing novel HIV therapies.

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.

There are two concurrent and novel major research pathways toward strategies for HIV control: (1) long-acting antiretroviral therapy (ART) formulations and (2) research aimed at conferring sustained ART-free HIV remission, considered a step toward an HIV cure. The importance of perspectives from people living with HIV on the development of new modalities is high, but data are lacking. We administered an online survey in which respondents selected their likelihood of participation or nonparticipation in HIV cure/remission research based on potential risks and perceived benefits of these new modalities. We also tested the correlation between perceptions of potential risks and benefits with preferences of virologic control strategies and/or responses to scenario choices, while controlling for respondent characteristics. Of the 282 eligible respondents, 42% would be willing to switch from oral daily ART to long-acting ART injectables or implantables taken at 6-month intervals, and 24% to a hypothetical ART-free remission strategy. We found statistically significant gender differences in perceptions of risk and preferences of HIV control strategies, and possible psychosocial factors that could mediate willingness to switch to novel HIV treatment or remission options. Our study yielded data on possible desirable product characteristics for future HIV treatment and remission options. Findings also revealed differences in motivations and preferences across gender and other sociodemographic characteristics that may be actionable as part of research recruitment efforts. The diversity of participant perspectives reveals the need to provide a variety of therapeutic options to people living with HIV and to acknowledge their diverse experiential expertise when developing novel HIV therapies.

Background

Development of human immunodeficiency virus (HIV) remission strategies requires precise information on time to HIV rebound after treatment interruption, but there is uncertainty regarding whether modern antiretroviral therapy (ART) regimens and timing of ART initiation may affect this outcome.

Methods

AIDS Clinical Trials Group (ACTG) A5345 enrolled individuals who initiated ART during chronic or early HIV infection and on suppressive ART for ≥2 years. Participants underwent carefully monitored antiretroviral interruption. ART was restarted upon 2 successive viral loads ≥1000 copies/mL. We compared participants of A5345 with participants of 6 historic ACTG treatment interruption studies.

Results

Thirty-three chronic-treated and 12 early-treated participants interrupted ART with evaluable time to viral rebound. Median time to viral rebound ≥1000 HIV RNA copies/mL was 22 days. Acute retroviral rebound syndrome was diagnosed in 9% of the chronic-treated and none of the early-treated individuals. All participants of the historic studies were on older protease inhibitor-based regimens, whereas 97% of A5345 participants were on integrase inhibitor-based ART. There were no differences in the timing of viral rebound comparing A5345 versus historic studies. In a combined analysis, a higher percentage of early-treated participants remained off ART at posttreatment interruption week 12 (chronic vs early: 2% vs 9%, P = .0496). One chronic-treated and one early-treated A5345 participant remained off ART for >24 weeks. All participants resuppressed after ART reinitiation.

Conclusions

Early ART initiation, using either older or newer ART regimens, was associated with a significant delay in the time to HIV rebound after ART interruption, lowering the barrier for HIV remission.

BACKGROUNDIdentifying factors that predict the timing of HIV rebound after treatment interruption will be crucial for designing and evaluating interventions for HIV remission.METHODSWe performed a broad evaluation of viral and immune factors that predict viral rebound (AIDS Clinical Trials Group A5345). Participants initiated antiretroviral therapy (ART) during chronic (N = 33) or early (N = 12) HIV infection with ≥ 2 years of suppressive ART and restarted ART if they had 2 viral loads ≥ 1,000 copies/mL after treatment interruption.RESULTSCompared with chronic-treated participants, early-treated individuals had smaller and fewer transcriptionally active HIV reservoirs. A higher percentage of HIV Gag-specific CD8+ T cell cytotoxic response was associated with lower intact proviral DNA. Predictors of HIV rebound timing differed between early- versus chronic-treated participants, as the strongest reservoir predictor of time to HIV rebound was level of residual viremia in early-treated participants and intact DNA level in chronic-treated individuals. We also identified distinct sets of pre-treatment interruption viral, immune, and inflammatory markers that differentiated participants who had rapid versus slow rebound.CONCLUSIONThe results provide an in-depth overview of the complex interplay of viral, immunologic, and inflammatory predictors of viral rebound and demonstrate that the timing of ART initiation modifies the features of rapid and slow viral rebound.TRIAL REGISTRATIONClinicalTrials.gov NCT03001128FUNDINGNIH National Institute of Allergy and Infectious Diseases, Merck.