EARLY ANTIRETROVIRAL TREATMENT HIV Cure Research Training Curriculum (CUREiculum) Early Antiretroviral (ART) Treatment Module by: Scientific Leads: Dr. Jintanat Ananworanich, U.S. Military HIV Research Program (MHRP) with input from Sidaction team (France) Community Lead: Jeffrey Taylor, Collaboratory of AIDS Researchers for Eradication (CARE) Contributor: Karine Dubé, CARE The HIV CURE research training curriculum is a collaborative project aimed at making HIV cure research science accessible to the community and the HIV research field. Last updated April 2015

Understand why early ART is an important HIV cure research strategy Explain that HIV latency is established very early during HIV infection Describe the Fiebig states during acute HIV infection Appreciate that early ART can result in a smaller reservoir size Identify examples of clinical studies involving early ART Module Objectives

The HIV infection pathway

Natural history of HIV infection Pantaleo G et al. NEJM, 1993

Why is early ART important? One of the most effective ways to contain the HIV reservoir, preserve immunity and reduce immune activation May optimize responses to immune-based interventions aimed at achieving HIV remission Is essential to prevent sexual transmission of HIV during acute infection May be a critical step in clinical research towards HIV cure

 Cell Death Resting State HIV persistence

 Before HIV Infection Viral Load Suppressed “Shock and Kill” Eliminate Infected Cells “Shock and Kill” Eliminate Infected Cells Vaccine Chronic HIV Infection Possible interventions: Latency reversing agents Broadly neutralizing antibody Gene-editing therapy Acute HIV Infection ART HIV RNA Strategies to eliminate HIV persistence

When is HIV latency established? HIV latency (or persistence) is established early in acute HIV infection in all CD4+ T cell subsets These cells carry integrated but transcriptionally silent HIV viral genome These cells carry integrated but transcriptionally silent HIV viral genome Small number of dormant HIV infected cells (including central and transitional memory CD4+ T cells) persist indefinitely and are not eliminated by ARV drugs or by the immune system HIV persistence is the main barrier to cure

 HIV latency is established in acute HIV infection  Latency persists despite early and long-term ART  Pool of latently infected cells is stable with little to no decay in the presence of long-term ART When is HIV latency established? Archin N et al. PNAS, 2011

 Establishment of the SIV reservoirs occurred as early as three days post- infection  Treatment with ART 3 days post-SIVmac 51 in rhesus macaques blunts viremia (viral RNA and proviral DNA) in the PBMCs but proviral DNA was already detected in tissues  Early ART at Days 3, 7 and 10 reduces the size of the viral reservoirs but does not prevent establishment of viral reservoir  Viral rebound occurred in all animals that were treated at Day 3 When is HIV latency established? Whitney JB et al. Nature, 2014

What are the Fiebig stages? Adapted from McMichael AJ, Nature Reviews Immunology, 2010 T0T0 Limit of detection of assay for Plasma viral RNA Virus concentration in extracellular fluid of plasma (copies per ml) Days following HIV-1 Transmission Initial infection Stage 1 Eclipse Phase

What are the Fiebig stages? Adapted from McMichael AJ, Nature Reviews Immunology, 2010 Eclipse Phase T0T0 Reservoir Established Symptoms Begin Limit of detection of assay for Plasma viral RNA Virus concentration in extracellular fluid of plasma (copies per ml) Days following HIV-1 Transmission

YY Plasma Viral RNA (copies per ml) Days following HIV-1 Transmission RNA P24 Antigen Specific EIA Possible presence of P24 Antigen Present on Western Blot Y What are the Fiebig stages?

Y RNA P24 Antigen Specific EIA Possible presence of P24 Antigen Present on Western Blot Y Y STAGE 1STAGE 2 STAGE 3 STAGE 4 What are the Fiebig stages?

Earlier ART = smaller reservoir size? Benefits of early ART is maximal in the first few weeks of infection 2 2 But subset of latently infected cells may persist indefinitely 3 3 Earlier treatment = smaller reservoir size 1 1 Key points:

What do we measure with total HIV DNA? Large Very small Small Total HIV DNA Replication- Competent Provirus Integrated HIV DNA Ho YC et al. Cell, 2014

Ananworanich J et al. Curr Opin HIV/AIDS, 2015 Early ART also alters the distribution of the reservoir in CD4+ T cell subsets

When patients treated during primary infection, the central memory T cells are preserved 2 2 ART limits persistence of HIV reservoir in all CD4+ T cell subsets (Chomont) 3 3 Long-lived viral reservoir may be the biggest obstacle to HIV cure 1 1 Key points: They may support latency through different mechanisms 6 6 But there is patient-to-patient variability 7 7 Resting CD4+ T cells also have different functional and phenotypic properties 5 5 When patients treated during primary infection, transitional memory T cells (with short half-life) contribute most to reservoir 4 4

Long-term ART initiated during AHI key to achieving low HIV reservoirs and normal T cell counts Patients treated during chronic infection Patients treated during primary acute infection Hocqueloux L et al. JAC, 2013

Pivotal clinical early ART studies Update from Thai Studies: Most participant enrolled at Fiebig I and III Very early ART protects all memory CD4+ T cell subsets from infection, including long-lived T CM cells ART in Fiebig I is associated with preservation of poly-functional gut Th17 cells; however, elevated plasma biomarkers of gut repair and microbial translation persist Most participant enrolled at Fiebig I and III Very early ART protects all memory CD4+ T cell subsets from infection, including long-lived T CM cells ART in Fiebig I is associated with preservation of poly-functional gut Th17 cells; however, elevated plasma biomarkers of gut repair and microbial translation persist RV254/SEARCH010: Early ART limits persistence of HIV reservoir in long-lived CD4+ T cell subsets RV254/SEARCH010: Early ART limits persistence of HIV reservoir in long-lived CD4+ T cell subsets

Nicolas Chomont Updated from Ananworanich J, 2013 CROI Long-lived central memory CD4+ T cells 100% 63% 0% Duration of HIV at ART initiation Early ART limits persistence of HIV reservoir in long-lived CD4+ T cell subsets (RV254/SEARCH010) Fiebig I Chronic

Post-treatment control present at sustained remission Sáez-Cirion et al. PLoS Pathogens, 2013 Viro-Immunological Sustained CONtrol after Treatment Interruption  VISCONTI

VISCONTI cohort Sáez-Cirion et al. PLoS Pathogens, 2013 Durable control of HIV infection after treatment interruption initiated during primary infection Different from HIV controllers (natural viral control = never received treatment) Treated within the first 2 months of infection Able to control viremia without ART > 9 years Most of VISCONTI patients had no protective HLA class I alleles (but neutral or high-risk alleles) and weak CD8+ T cell responses (no favorable genetic profile) Low HIV DNA level and shorter time to ART initiation from onset of infection predicted post-treatment control (PTC) Mechanism of viral control is different between PTC and elite controllers Need more research to understand the mechanism of viral control Durable control of HIV infection after treatment interruption initiated during primary infection Different from HIV controllers (natural viral control = never received treatment) Treated within the first 2 months of infection Able to control viremia without ART > 9 years Most of VISCONTI patients had no protective HLA class I alleles (but neutral or high-risk alleles) and weak CD8+ T cell responses (no favorable genetic profile) Low HIV DNA level and shorter time to ART initiation from onset of infection predicted post-treatment control (PTC) Mechanism of viral control is different between PTC and elite controllers Need more research to understand the mechanism of viral control VISCONTI Cohort

Pediatric studies: a form of early ART

Long term remission for 27 months 30 hours HIV detected in blood plasma BIRTH 18 months Begins ARTStops ART 46 months No HIV detected in blood plasma 23 months HIV detected in blood at 2 separate time points Mississippi child: timeline of events Persaud D et al. NEJM, 2013 Persaud et al. IAS 2014

Started ART at <2 days of life, remained on ART for 18 months and was able to remain suppressed for 27 months without ART Transient but encouraging HIV remission A remarkable progress for the field: –Re-affirmed the concept that HIV could persist in latent HIV reservoirs –Evidence that early ART could prolong the time to viral load rebound –Showed that current HIV reservoir test may not be sensitive enough –Showed that only a small number of latently infected cells could rekindle HIV infection Started ART at <2 days of life, remained on ART for 18 months and was able to remain suppressed for 27 months without ART Transient but encouraging HIV remission A remarkable progress for the field: –Re-affirmed the concept that HIV could persist in latent HIV reservoirs –Evidence that early ART could prolong the time to viral load rebound –Showed that current HIV reservoir test may not be sensitive enough –Showed that only a small number of latently infected cells could rekindle HIV infection Mississippi Child Pediatric studies: a form of early ART

Ethical and social considerations How early is “early enough” 2 2 Treatment interruptions not medically recommended (standardized and controlled clinical studies; active and frequent monitoring) Treatment interruptions not medically recommended (standardized and controlled clinical studies; active and frequent monitoring) 3 3 Early ART will not be “curative” (e.g. adults will not be cured by early ART alone; risk of curative misconception) Early ART will not be “curative” (e.g. adults will not be cured by early ART alone; risk of curative misconception) 1 1 Potential impacts (positive or negative) on interpersonal relationships 5 5 Perception of “vulnerability” vs. “healthy” patients (e.g. medical vulnerability vs. how patients perceive themselves) Perception of “vulnerability” vs. “healthy” patients (e.g. medical vulnerability vs. how patients perceive themselves) 4 4

Implementation challenges Difficult to identify people in AHI Recruitment and time of initiation of antiretroviral treatment Patient-to- patient variability given stochastic nature of rebound Scalability Difficult to compare studies (variable timing of ART initiation and ways to measure reservoir)

Conclusions and key points ART started during AHI can limit the size of the HIV reservoir Treatment in earliest AHI (Fiebig I) may skew distribution of latently infected cells to shorter lived memory CD4+ T cells HIV persistence established early in AHI in memory CD4+ T cells and can persist indefinitely ART in AHI may be the first critical step in clinical research aimed at HIV cure/remission

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