current clinical therapies for hiv...

Current Clinical Therapies for HIV

Remission

David Margolis MDUNC HIV Cure Center

Cohen J. Science 2014

Aiming for sustained remission off ART

Luzuriaga et al. NEJM 372;8: 786

Effect of vorinostat, hydroxychloroquine and maraviroc combination therapy on viremia

following treatment interruption in individuals treated

during acute HIV infection (Fiebig III-IV)

Eugène Kroon, Jintanat Ananworanich, Keith Eubanks,

Jintana Intasan, Suteeraporn Pinyakorn, Nicolas Chomont,

Sharon R Lewin, Sarah Palmer, Lydie Trautmann, Hua Yang,

Nitiya Chomchey, Nittaya Phanuphak, Ken Cooper,

Praphan Phanuphak, Mark de Souza

on behalf of the SEARCH 019 study group

HIV Rebound after ART Interruption

Median time to first VL detection: 22 days (range 14 to 77 days)

ART resume at VL > 1000 c/ml

Stochastic

Reversal

of Latency

Chronically producing

cell

Host cell modification

KO: CCR5 (Sangamo)KI: sh5/C46 (Calimmune)

• Challenges moving forward:– Is cytoreductive therapy needed?

Acceptable?

– Is there X4 escape?

– Scalability? Cost?

• CCR5-modified CD4 T cells at 1 week post infusion constituted 13.9% of

circulating CD4 T cells

• Modified cells had an estimated mean half-life of 48 weeks

• After ART interruption, decline in circulating CCR5-modified cells (−1.81 cells

per day) was significantly less than the decline in unmodified cells (−7.25 cells

per day) (P = 0.02)

• HIV RNA became undetectable in one of four patients who could be evaluated

A first step to eliminate

latent HIV infection

Latency

Reversal

A second step to eliminate

latent HIV infection

Latency Reversal and Clearance Candidates

• Latency Reversing Agents (LRAs)

– HDAC inhibitors• “lack potency and killing as single agents” (Mellors)

• “HDAC inhibitors do not kill non-transformed cells at clinical exposures” and “Appropriate serial dosing regimens of HDAC inhibitors have not yet been performed” (Margolis)

Apologies, too many references to cite!

Pt. 1 Pt. 2 Pt. 3 Pt. 4 Pt. 5 Pt. 6 Pt. 7 Pt. 80

20

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VOR 400 mg

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2012!

Rasmussen Lancet ID 2014

Thrice weekly cycles of Panobinostat

**!**!

**!**!*!

Days!

Lewin CROI 2013!14 daily doses of vorinostat! Elliot&PLoS&Path&2014&

Sogaard IAS 2014

Total CD4 cell-associated unspliced HIV-1 RNA!

Weekly Romidepsin !

Sogaard&PLoS&Path&2015&




• “HDAC inhibitors do not kill non-transformed cells at clinical exposures” and “Appropriate serial dosing regimens of HDAC inhibitors have not yet been performed” (Margolis)


– PKC agonists• most potent activators but toxicity of concern

• Bryostatin clinical trial did not achieve effective drug exposures

– TLR agonists: • activate HIV expression and immune control in SIV/macaques

TLR7 Agonists Induce Transient Plasma Viremia

Time after TLR7 agonist dose (Hours)

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Placebo GS-986 (0.1

mg/kg)

GS-9620 (0.05 mg/kg) GS-9620 (0.15

mg/kg)

• Reduced frequency of blips 38-75% (doses 3-10)

• No more blips from animals dosed after 3 month

pause (doses # 11-19)

Whitney et al., CROI 2016

Phase I/II trial of GS-9620 in HIV-

infectionDesign:

• 3 escalating dose cohorts– 1 mg, 2 mg, 4 mg every 2 weeks for 6 doses

• Placebo-controlled, randomized, double-blinded (6 active, 2 placebo per cohort)

Study Population:

• HIV-infected adults (n=24)

• Virologically suppressed ≥12 months on ART

Study Monitoring:

• Close follow-up – VL 2-3x/w

• Repeat dosing only if VL <50 copies/mL

• Safety review prior to initiation of each cohort

Current status: Enrolling Cohort 3




• “HDAC inhibitors do not kill non-transformed cells at clinical exposures” (Margolis)

– PKC agonists• most potent activators but toxicity of concern

• Bryostatin clinical trial did not achieve effective drug exposures

– TLR agonists: • activate HIV expression and immune control in SIV/macaques


– Other Epigenetic targets• Bromodomain inhibitors

• Histone methyltransferase inhibitors (eg. EZH2 inhibitors)

• Others in development

– High-throughput library screening efforts

Merck HIV Latency HDAC Inhibitor

Synergy Screen

HIV LTR Induction

With 250nM SAHA2,900,000 Compounds

Confirmatory Assays, n=3HIV LTR Induction

With 250nM SAHA

Dose Response Assays, n=2

HIV LTR Induction

Without SAHA

HIV LTR Induction

With 250nM SAHA

NFkB BLA Reporter

Counter Screen

Toxicity @ 48 Hours

CTG

Data Analysis/

Hit Selection

Follow-up

Analysis~4,500 Compounds

Initial Screen, n=3

Objective: To identify compounds that potentially act synergistically

with HDACis to induce HIV transcription

Compounds with unknown mechanism

Known HDAC InhibitorsKnown Farnesyl-Transferase Inhibitors

66.5%16.1%

17.4%

Testing interventions in vivo

ART *After

intervention

• Leukapheresis for QVOA and ca-HIV RNA

• SCA• Immune assays• Host cell assays & biomarkers• Novel assays, eg. Quanterix

Simoa

• Leukapheresis for QVOA and ca-HIV RNA

• SCA• Immune assays• Host cell assays & biomarkers• Novel assays, eg. Quanterix

Simoa

Baseline

LRAsImmunodulators

HIV vaccinesNovel approaches

Reduction in:• Resting CD4

cell infection• Low-level

viremia

HIV RNAin cells or culture

HIV DNA, RNA, antigen & viruses

Ho, Cell 2013

Ericksson, PLoS Path 2013

HIV Antigen

(protein)

detector

The “Real”

Reservoir

HIV DNA

QVOAReplication-

competent

virus

1 2 3 4 5 6 7Time on ART (years)

-

0.0001

0.001

0.01

0.1

1

10

100

0

Fre

quency

(per

10

6cells

)

0.00001

Margolis, Garcia, Hazuda, Haynes Science 2016

Time to eradication > 73.4 years

Persistent HIV infection despite ART

Residual

Replication

or Cell

Proliferation

Viral

Activation &

Clearance

or Cell Death

Crooks et al. JID 2015

• Given assay variance, a more than 6-fold RCI decrease would have likelihood 0.023 (2.3%)

• Therefore a measurable goal is therapy that can reduce the latent reservoir by half a log

Challenges to clearing persistent infection after latency reversal

• Recent absence of antigen – low frequency of HIV-specific antiviral responses

• Immune dysfunction, deletion, or exhaustion• Archived viral diversity, including immune escape• Viral antigen is rare, dispersed,

compartmentalized, and may be transient• Latency Reversing Agents (LRAs) are host-

targeted, and alone or in combination may alter antiviral immune response

Latency Reversal Agent Discovery

• New metric of viral antigen production or

presentation

- Antigen required to allow clearance

• Assessment of LRA effect on immune function as

part of development path

- Immune function required for clearance

Quanterix Simoa™ Technology

Quanterix Simoa Platform• Ultrasensitive platform (sub-pg/mL sensitivity)

• Full automation (samples in – data out)

– Rapid readout (~1 hr), >500 data points per day

• Broad dynamic range (>4 logs)

• Commercial p24 assay applied to plasma and serum (Chang L, et al. J Virol Methods. 2013;188(1-2):153-160.)

• In-house Merck assay optimized to reduce nonspecific binding and enhance sensitivity, thus enabling p24 quantitation in cell lysates

1. Single-protein molecules are captured and labeled on individual beads using standard ELISA reagents

2. Beads + substrate are loaded in individual femtoliter wells. Oil added to seal well

3. Digital or analog fluorescence readout of individual beads

http://www.quanterix.com/Howell et al. submitted

http://www.quanterix.com/

CD8+

LatencyReversing

Agent

PBMCs

No Effectors

or or

AddEffectors

LimitingDilution

Co-culture

Measure HIV

Productionat 2 weeks

CD8+ by negative selection

CultureResting CD4+cells

Resting CD4+ cells bynegativeselection

RemoveEffectors

CD8+,HXTCs

,or

DARTs

Latency Clearance Assay

Patient

425Patient

532Patient

250

0

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ira

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CD8HXTC

††

††

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PHA

VOR

†p<0.05 compared to No Effector

††p<0.05 compared to BOTH

HXTCs Reduce Recovery of Virus from autologous

resting CD4+ T cells stimulated with:

††

††

†

†

Sung et al. JID 2015

Latency Reversal and Clearance Candidates• Natural and Engineered Antibodies

– Broadly-neutralizing monoclonal antibodies (bnMAbs)• Can delay rebound and promote cell clearance in humans (3BNC117)

• Resistance can rapidly develop (VRC01, 3BNC117)

• Effect in individuals on ART? (VRC01)

– Engineered bnMAb• Can prolong half-life and enhance Fc effector functions (e.g. PGT-151)

– Bispecific Ab (anti-HIV/anti-host, e.g. CD3 or CD16)• Enhance effector function ex vivo and in animal models


A5342/VRC01 Study• Double-blind, randomized, placebo-controlled, Phase I study

• 40 participants (20 per arm)

• VRC01 40 mg/kg IV at Day 0 & 21 (Arm A) or Day 42 & 63 (Arm B)

Trial Completed and Analyses Underway!

• SIV-infected monkeys were treated with a 90-day course of ART initiated 5 weeks post infection

• 9 weeks post infection infused with primatizedmonoclonal antibody against the α4β7 integrin every 3 weeks until week 32

• All animals subsequently maintained low to undetectable viral loads and normal CD4+ T cell counts for more than 9 months, after all treatment was withdrawn.

• Human trial underway at NIH

Dual Affinity ReTargeting (DARTs) Molecules for HIV

• Do not require pre-existing HIV specificity• Not impacted by archived CTL escape variants

• Anti-Env arm based on well characterized mAbs that have: • Are broad neutralizing antibodies -- bind virions and infected cells: DH542 (V3

glycan bnAb), CH557 (CD4bs bnAb), DH511-K3 (gp41 MPER bnAb)• Are ADCC mediating antibodies -- bind only infected cells: (7B2, gp41

immunodominant), A32 (C1)

Dual Affinity Re-Targeting proteins direct T cell –mediated cytolysis of latently HIV-infected cells.Sung, JA, Pickeral, J, Liu, L, Stanfield-Oakley, SA, Lam, CY, Garrido, C, Pollara, J, LaBranche C. Bonsignori, M. Moody, MA, …..Haynes, BF, Nordstrom JL, Margolis, DM, Ferrari, G. JCI 2015

Sung et al.:• Screened ADCC, non-neutralizing

Abs that bound HIV-infected CD4 T cells for optimal ADCC

• Constructed DARTs with non-Neutralizing mAbs A32XCD3 and 7B2XCD3

• Showed DARTs + CD8 CTL eliminated HIV-infected CD4 T cells in vitro by CD8 T cell-mediated cytolysis.

Sloan et al.:• Constructed bnAb PGT145 (V1V2),

PGT121 (V3 glycan), VRC01 (CD4 bs), and 10E8 (distal MPER)---compared to A32 and 7B2 non-neutralizing DARTs

• Best were PGT121, A32 and 7B2 DARTs

Targeting HIV Reservoir in Infected CD4 T cells by DARTs that bind Envelope and Recruit CTLs. Sloan DD et al. PLoS Pathogens, 2015

HIVxCD3 DART-mediated virus clearance in 4 of 4 patients (longer time needed for Pt 795)

V O R -E x p o s e d L a te n tly In fe c te d C e lls

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Sung, et al. JCI 2015

HIVxCD3 DART Mediated Clearance of Resting

Patient CD4 Cells Exposed to Vorinostat

• Immune Checkpoint Blocking Antibodies– Major advance in cancer immunotherapy

– Reverse immune exhaustion

– Examples: Anti-PD-1/PD-L1, LAG-3, 2B4, CD160, TIM-3, others

• Cellular therapies– CD8+T-cells with chimeric antigen receptors

– Ex-vivo Effector cell expansion/re-infusion

– Activated NK cells

• Therapeutic Vaccines– Multiple approaches

– Chimp Adeno vector, CMV vector, VSV vector, Ad26/MVA vectors, Dendritic cells

– Can induce broad CTL responses

Covering immune escape variants is critical!



Tools to Test Latency Reversal and

Clearance

Autologous DC vaccineMinimal effect of VOR on immune function

Clutton

Sci Rep 2016

Baseline Multidose

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

2 5 0 0

p < 0 .0 0 0 1

HIV

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ga

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er

we

llArchin

Keystone Symposium on

HIV Persistence 2016

Persistent LRA activity of multiple VOR doses

Combination Latency Reversal and

Clearance Trial I

Step4

AGSEOS

Term~Week15-

Week24

~Week73-

Week89

Visit8 27

AGSManufacturing EOS

visits-nodosing Leukapheresis&rc-RNA IMandProviral Viralinhibitionandlatencyclearanceassays

visits-Vorinistatdoses Safetylabs SCA Acetylation

visits-AGS-004injections PKSamples ExploratoryImmunology

rc-RNAmeasurementdeterminesprogress

SingleDose

Step7

AGSDosing

Step8

MultipleVORDosing

Step1

Screen

Step2

Enrollment

Step3

Interval

Step5

AGSDosing

Step6

MultipleVORDosing

~Week39-Week54

Visits14-17 Visits18-22

~Week52-Week73

Visits23-26

~Week64-Week81

PairedDoses

Approximately

Weeks0-8

InjectionsX4

IntervaldosingX10doses

InjectionsX4

IntervaldosingX10doses

~Week27-Week46

Visit9-13

BASELINE

~Week6-Week13

Visits1&2 Visit3&4

~Week10-Week

18

Vists5-7

Vaccine Vaccine

LRA x 10

Vaccine = Argos dendritic cell therapy

LRA = vorinostat

LRA x 1 LRA x 2LRA x 10

Combination Latency Reversal and

Clearance Trial II

ART

STEP1PretreatmentPhaseExhibit Ex-vivoresponsetoVOR

STEP2:SingleVOR400mgdose

STEP3:HXTCsproduced

STEP4:FirstCombinationtreatmentVORevery72hoursx10dosesand2HXTCInfusions

RESTPERIOD

STEP5:FirstCombinationtreatmentVORevery72hoursand2HXTCInfusions

STEP 6:ImmuneResponsemonitoring

~4weeks ~8weeks

~6-8weeks

4weeks 2-4weeks

4weeks ~45weeks

Visits12 33.1 45 6789101112 13141516171819 20 2122232425

ImmuneResponseAssays HXTCInfusion LeukapheresisSingleCopyAssayOtherResearchAssays

VORevery72hoursx10doses


cART

STEP1PretreatmentPhaseExhibit Ex-vivoresponsetoVOR

STEP2:SingleVOR400mgdose

STEP3:HXTCsproduced

STEP4:FirstCombinationtreatmentVORevery72hoursx10dosesand2HXTCInfusions

RESTPERIOD

STEP5:FirstCombinationtreatmentVORevery72hoursand2HXTCInfusions

STEP 6:ImmuneResponsemonitoring

~4weeks ~8weeks

~6-8weeks

4weeks 2-4weeks

4weeks ~45weeks

Visits12 33.1 45 6789101112 13141516171819 20 2122232425

ImmuneResponseAssays HXTCInfusion LeukapheresisSingleCopyAssayOtherResearchAssays



cART

HX

TC

HX

TC

HX

TC

HX

TC

HX

TC

Cath Bollard

Clio Rooney

Steps to eliminate

HIV infection

Latency

Reversal

Finally: the addition of durable vaccine protection if rebound or reexposure occurs

current clinical therapies for hiv...

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