saye khoo - virology educationregist2.virology-education.com/2014/2nd_hivfuture/5_khoo.pdf · saye...

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Saye Khoo www.hiv-druginteractions.org & www.hep-druginteractions.org sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial content remains independent. Research Grants: Merck, ViiV, Janssen, Novartis Speakers bureau: Merck, Janssen, AbbVie, ViiV, Gilead Travel grants: Gilead, ViiV, Declaration of Interests

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Page 1: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Saye Khoo

•www.hiv-druginteractions.org & www.hep-druginteractions.org

sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead.

Editorial content remains independent.

•Research Grants: Merck, ViiV, Janssen, Novartis

•Speakers bureau: Merck, Janssen, AbbVie, ViiV, Gilead

•Travel grants: Gilead, ViiV,

Declaration of Interests

Page 2: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

PK Challenges on Reservoirs

Cells (biology)

Location of Cells

(compartments)

Barrier to cure

Persistent inflammation

Low-level viraemia

Resistance

Transmission

HIV Drug

HIV

HIV

Reservoirs Consequences

Page 3: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Quality of Evidence for PK Reservoirs

Measure drug

concentrations in

cells/compartments

• direct observation

• target concentrations not defined

• protein binding, drug metabolism

• large inter-patient variability

• technical challenges

Comparison of viral

dynamics

• plasma-compartment VL discordance

• VL dynamics upon starting treatment

• significant inter-patient variability

• relevant to transmission

Comparison of drug

resistance profiles

• direct relevance

• track evolution of resistance

Page 4: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

PK Compartments

CNS

PK, VL dynamics,

Resistance

Breast milk

PK, VL dynamics,

Resistance

Lungs

VL dynamics

GALT, lymph nodes

PK, VL dynamics

Generally concordant

nucleotide sequences

Genital tract

PK, VL dynamics,

Resistance

Jofesson et al PLoS Pathogens 2013; 9: e1003432

Placenta

PK

Page 5: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Are some ARVs more effective in the CNS than others ?

• Some [ARV] in CSF ≤ IC50-95

• CPE CSF HIV RNA and HIV genetic diversity

• Switch to CPE regimen – HIV CSF RNA, cognitive function

• Discordant resistance mutations

• Some ARVs neurotoxic in-vitro

ARGUMENTS FOR

Letendre et al. Arch Neurol 2008;65:65

Cysique et al. BMC Neurol 2011;11:148

Robertson et al. J Neurolvirol 2012;18:388

Peluso et al AIDS 2012;26:1765

Smit et al. J Virol 2004;78:10133

Heaton et al. Neurology 2010;14:536

Simioni et al. AIDS 2010;24:1243

Giancola et al. JAIDS 2006;41:332

Smurzynski et al. AIDS 2011;25:357

Ellis et al. Clin Infect Dis 2014; 58: 1015

Page 6: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Are some ARVs more effective in the CNS than others ?

• Some [ARV] in CSF ≤ IC50-95

• CPE CSF HIV RNA and HIV genetic diversity

• Switch to CPE regimen – HIV CSF RNA, cognitive function

• Discordant resistance mutations

• Some ARVs neurotoxic in-vitro

ARGUMENTS FOR

Letendre et al. Arch Neurol 2008;65:65

Cysique et al. BMC Neurol 2011;11:148

Robertson et al. J Neurolvirol 2012;18:388

Peluso et al AIDS 2012;26:1765

Smit et al. J Virol 2004;78:10133

Heaton et al. Neurology 2010;14:536

Simioni et al. AIDS 2010;24:1243

Giancola et al. JAIDS 2006;41:332

Smurzynski et al. AIDS 2011;25:357

MR spectroscopy (N-acetyl aspartate)

Schweinsburg. J Neurovirol 2005;11:356

Frontal white

matter 11%

Tovar-y-Romo et al. JPET 2012;343:696

• Dendritic spines of neurons

• Ca signalling

• Apoptosis & survival

8OH EFV is Directly Neurotoxic

Page 7: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Are some ARVs more effective in the CNS than others ?

• Some [ARV] in CSF ≤ IC50-95

• CPE CSF HIV RNA and HIV genetic diversity

• Switch to CPE regimen – HIV CSF RNA, cognitive function

• Discordant resistance mutations

• Some ARVs neurotoxic in-vitro

ARGUMENTS FOR

• CSF viral escape is uncommon

• Some observational studies show no association between CPE and cognitive function

(assay sensitivity, NPS tests, normative data)

• PK in CSF may not reflect PK in microglia or brain macrophages

ARGUMENTS AGAINST

Letendre et al. Arch Neurol 2008;65:65

Cysique et al. BMC Neurol 2011;11:148

Robertson et al. J Neurolvirol 2012;18:388

Peluso et al AIDS 2012;26:1765

Smit et al. J Virol 2004;78:10133

Heaton et al. Neurology 2010;14:536

Simioni et al. AIDS 2010;24:1243

Giancola et al. JAIDS 2006;41:332

Smurzynski et al. AIDS 2011;25:357

Nightingale et al. Lancet ID (in press)

Page 8: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

ARV Penetration into Genital Tract

• Physiochemical Characteristics – QSAR predictions suggest Vd,

MRP1 substrate, MRP4 substrate drugs penetrate female genital tract

• Gender specific and drug-specific – rather than class-specific

• Viral dynamics generally concordant with exceptions

• PARTNERS suggests plasma VL is a good surrogate

• Insight from PreP pharmacokinetic studies - Rectal TFV / TFV-DP levels higher than vaginal - TFV-DP in VT: TFV gel >>> TDF (po), some rectal exposure also

Thompson et al. AIDS Res Hum Retrovirol 2014;29:1

Else et al. AVT 2011;16:1149

Hendrix et al PLoS One 2014; 8(1): e55013

Page 9: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Else et al. Antiviral Therapy 2011; 16:1149 ; Cohen, et al. Annals Int. Med, 2007

Page 10: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Breast Milk

• residual transmissions (3.3-5.6% in Kesho Bora trial)

• > three quarters vertically infected infants in Kisumu Breastfeeding Study (ZDV/3TC + NVP or NFV) had resistance to both NVP and 3TC

• in the BAN study (cART initiated post-partum) almost a third of HIV+ infants had multiclass resistance

Zeh et al. PLoS Med 2011;8:e1000430

Fogel et al. CID 2011;52:1069

Kesho Bora Study Group, Lancet ID 2011 Mar;11(3):171

van der Perre Science Trans Med 2012;4:

Tuaillon et al; J Immunol 2009

Valea et al Revrovirology 2011

Chasela NEJM 2010 ;362 :2271

Page 11: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Importance of cell-to-cell transmission in Breast Milk

• cell-to cell infection may be important route of early postpartum transmissions through breastfeeding

• Macrophages

• T & B cells more likely to be activated, memory

Tuaillon et al; J Immunol 2009

van der Perre Science Trans Med 2012;4:

Page 12: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Valea et al Revrovirology 2011;8:34

• CD4+ T cells freshly purified from BM and plasma

• T cells in BM more likely to be activated, memory cells

• Spontaneous HIV antigen-secreting T cells present in BM and plasma

• HIV detected in 4/7 aviremic, and 5/8 viraemic mothers

• ART does not completely suppress cell-associated viral replication

Importance of cell-to-cell transmission in Breast Milk

Page 13: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Breast Milk Transmissions – Phylogenetic analyses

• Nested within RCT of vitamin supplementation • Mothers were free to choose breastfeeding after counselling • ARVs not available during study • MTCT (N=61) – infant PCR- (6w) subsequently became PCR+

Koulinska et al. J AIDS 2006;41:93-99

Page 14: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Transplacental transfer of HIV drugs

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

Cord:maternal plasma

Amniotic:maternal plasma

10.7 2.8

Pinetti et al AVT 2010;15:127

Ivanovic Curr HIV Res 2009;7:620

Gavard. Am J Obstet Gynecol 2006;195:296

Bawdon. Obstet Gynecol 6:244, 1998

Sudharkaran Antimicrob Agents Chemother 2005;49:1023-8

Forestier Am J Obstet Gynecol 185:178, 2001

Ceddaldi P-F, et al: Am J Obstet Gynecol 2008;198:433. Mirochnick IWCPHT Sorrento 2010; Abst03

Moisan IWCPHT Sorrento 2010; Abst 01

Rati

o

Page 15: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

HIV in the Lung

xx

• Acute (opportunistic & non-opportunistic) infections • Chronic Lung Disease – inflammation, emphysema, fibrosis • Increasing prevalence despite ART

• ? HIV related factors

Page 16: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Drug Targeting of Cellular Reservoirs

Ford et al. JAC 2004;54:982

CD4+ T cells – including latent infected resting memory T cells GALT Follicular Dendritic Cells Haemopoietic Stem Cells Monocyte-macrophages

Other cells ?

Buzon et al. Nat Med 2014;20:139

• Hierarchy of PI accumulation methodological differences

• Activated vs resting (ex-vivo) ZDV-TP, CBV-TP

Page 17: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

ARV concentrations by compartment

relative to PBMC concentrations

Fletcher C V et al. PNAS 2014;111:2307-2312

Different patterns of HIV RNA decay

from FDCs in lymph nodes

Association between decay rate of

virions from FDC pool and

intracellular drug levels

ARV Concentrations in Lymphatic Tissue

• HIV+ patients starting ART (N=12; including EFV [6], ATVr [4], DRVr [2]) • Serial ileum/rectal/LN biopsies through M1-M6 • Flash-frozen tissue, minced and disaggregated • PBMCs and tissue extracts washed twice, lysed • LC-MS/MS analysis • Patterns of RNA decay in tissue: no change

initial decay, then plateau constant reduction

Page 18: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Macrophages

• A primary tissue reservoir of HIV

• Significant differences from T cells

• longer lived source of infection

• less prone to cytopathic effect

• terminally differentiated limited dNTP pools (22-320-fold [dNTP]

• ? Different TK activity (TK2 vs TK1 in lymphocytes)

• host restriction factors- SAMHD1, APOBEC3G, etc

Kumar et al. Mol Cell Ther 2014;2:10

Carter. Ann Rev Microbiol 2008;62:425

Gavegnano et al. Antivir Chem Chemother 2009;20:63

Perno et al. Antivir Res 2006;71:293

Aquaro et al. Antiviral Res 2002;55:209

Galvegano et al. Mol Biol Int 2012;625983

Gavegano et al. AAC 2013;57:1262

Aquaro et al. J Leukoc Biol 2006;80:1103

Page 19: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Could PK of ARVs differ in Macrophages ?

Ex-vivo / in-vitro studies of PK in macrophages

intracellular PK • Intracellular [ZDV- TP], [CBV- TP], [3TC- TP], [FTC-TP] : M<<< T cells • Intracellular [TFV/TFV-DP]: M T cells • Intracellular [RAL]: M << T cells (independent of activation)

Arner et al. JBC 1992;267:10968

Perno et al. AVT 2006;71:293

Aquaro et al. J Leukoc Biol 2006;80:1103

Gavegano et al. AAC 2013;57:1262

Aquaro et al. Antiviral Res 2002;55:209

Galvegano et al. Mol Biol Int 2012;625983

PD • In-vitro models suggest NRTIs more active in MM than CD4+ lymphocytes • ddNTP:dNTP ratios are higher • EC50 of NRTI/NNRTI : chronic >>> acutely infected M • RAL: poor potency in M • EC50 of PI : chronically infected M >> T cells, but still retained some

activity

Page 20: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Drug Metabolism within Compartments

CNS

CYP P450 (2B6, 3A4, 2D6)

UGTs

Transporters (ABCG2, ABCC5/10,

ABCB1, SLCO1A2

Breast milk

CYP P450 (1B1, 4Z)

may inhibit gut UGT1A1

Transporters (ABCG2, ABCC1/3/6,

SLC15A2, SLC29A1, SLCO2B1/3A1

Lungs

CYP P450 (1A1, 2C19)

Transporters (ABCC1/10,

ABCG2; SLCO3A,

SLC22A7, SLC15A2)

GALT, lymph nodes

Transporters (ABCB1,

ABCC1/2/10, ABCG2;

SLCO3A1, hENTs)

CYPs (3A4, 2B6)

Genital tract

Transporters (ABCG2,

ABCC1/10/12,; SLCO3A1)

Placenta

CYPs (1A1, 2E1, 3A4/5)

UGTs

transporters (ABCB1, ABCC1,

ABCG2; SLC22A3 [OCT3],

SLC29A1,2 [hENT1&2)

Brain CYP 2B6

Page 21: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Can we improve existing drugs?

• ‘Boost’ concentrations within compartments through transporter inhibition

• Development of pro-drugs – eg TAF

• Cell-targeting Nanoformulations – eg folate-coated nanoformulations

Page 22: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Tenofovir Alafenamide (GS7340)

• TAF : intra-PBMC TFV-DP (50x) , plasma TFV (90%) compared to TDF

• TFV in rectal secretions, TFV-DP following single dose of TAF 3 days before to macaques

• Despite tissue drug levels, did not protect macaques from rectal SHIV infection

García-Lerma J G et al. J. Virol. 2011;85:6610-6617

Page 23: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Can we improve existing drugs?

• ‘Boost’ concentrations within compartments through transporter inhibition

• Development of pro-drugs – eg TAF

• Cell-targeting Nanoformulations – eg folate-coated nanoformulations

Kanmogne et al. Int J Nanomed 2012; 7: 2373

Nano-RTV (orange-yellow) uptake by

human brain microvascular endothelial

cells cocultured with monocytes

Gautam et al. 2014 AAC 6th Oct

Page 24: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Cell-to-cell transmission FIB-SEM imaging reveals virological synapses

between infected and uninfected T cells.

Do T et al. J. Virol. 2014;88:10327-10339

• May be important in MTCT (breast milk transmission), CNS, GALT, sexual transmission

• Several orders of magnitude more efficient than cell-free diffusion

large MOI delivered through physical contact densely packed cells

• Can this evade ART ? NRTIs sensitivity than cell-free infection PIs and EFV retain activity in-vitro

Sigal et al. Nature 2011;477:95

Titanji et al. Retrovirol 2013;10:161

Agosto et al. PLoS Pathog 10(2): e1003982

Page 25: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Questions

Modern ART does not fully control HIV replication

• How much more can existing ARVs be enhanced to target reservoirs ? (and what are the implications for deintensification)

• Can existing ARV classes ever gain adequate control of residual replication ?

• What are the implications for mortality, morbidity, resistance and transmission ?

Page 26: Saye Khoo - Virology Educationregist2.virology-education.com/2014/2nd_HIVFuture/5_Khoo.pdf · Saye Khoo • & sponsorship from Janssen, ViiV, AbbVie, Merck, BMS, Gilead. Editorial

Acknowledgements

University of Liverpool David Back

Laura Else

Catriona Waitt

Andrew Owen

Marco Siccardi

Sam Nightingale

Anna Maria Geretti

Malawi-Liverpool-Wellcome Unit,

Blantyre Henry Mwandumba

Christine Kelly

St Stephens AIDS Trust Marta Boffito

Akil Jackson

Oxford University Clinical

Research Unit, Ho Chi Minh Estee Torok

.. and many others ....