Download Current Clinical Therapies for HIV Remission

Current Clinical Therapies for HIV
Remission
David Margolis MD
UNC HIV Cure Center
Aiming for sustained remission off ART
Cohen J. Science 2014
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
Host cell modification
Stochastic
Reversal
of Latency
Chronically
producing
cell
KO: CCR5 (Sangamo)
KI: sh5/C46 (Calimmune)
•
•
•
CCR5-modified CD4 T cells at 1 week post infusion constituted 13.9% of
• Challenges
moving forward:
circulating CD4
T cells
– an
Is cytoreductive
Modified cells had
estimated meantherapy
half-life needed?
of 48 weeks
Acceptable?
After ART interruption, decline in circulating CCR5-modified cells (−1.81 cells
– Is there X4 escape?
per day) was significantly less than the decline in unmodified cells (−7.25 cells
– Scalability? Cost?
per day) (P = 0.02)
•
HIV RNA became undetectable in one of four patients who could be evaluated
AAsecond
first step
step
to to
eliminate
eliminate
latent
latentHIV
HIVinfection
infection
Latency
Reversal
Latency Reversal and Clearance Candidates
•
Latency Reversing Agents (LRAs)
– HDAC inhibitors
800
*
*
!
! *
*
!
*
*
!
• “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)
600
Relative HIV-1 gag RNA copies
14 daily doses of vorinostat! Elliot&
PLoS&
Path&
2014&
Lewin
CROI
2013!
Baseline ART
VOR 400 mg
400
200
100
60
40
20
Days!
0
Pt. 1
Pt. 2
Pt. 3
Pt. 4
Pt. 5
Pt. 6
Pt. 7
Thrice weekly cycles of Panobinostat
2012!
Pt. 8
Weekly Romidepsin !
Total CD4 cell-associated unspliced HIV-1 RNA!
Sogaard IAS 2014
Rasmussen Lancet ID 2014
PLoS&Path&
2015&
Apologies, too manySogaard&
references
to cite!
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)
– 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
Apologies, too many references to cite!
TLR7 Agonists Induce Transient Plasma Viremia
Plasma SIV
(log10 RNA copies/mL)
103
GS-986 (0.1
Plasma SIV RNA copies/ml
Placebo
mg/kg)
102
GS-9620 (0.05 mg/kg)
mg/kg)
103
GS-9620 (0.15
Vehicle
V1
V2
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
V1
V2
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
0
24
48
72
168
102
Vehicle
Time after TLR7 agonist dose (Hours)
•
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 HIVinfection
Design:
• 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
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”
(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
Apologies, too many references to cite!
Merck HIV Latency HDAC Inhibitor
Synergy Screen
Objective: To identify compounds that potentially act synergistically
with HDACis to induce HIV transcription
2,900,000 Compounds
HIV LTR Induction
With 250nM SAHA
Initial Screen, n=3
HIV LTR Induction
With 250nM SAHA
Confirmatory Assays, n=3
Dose Response Assays, n=2
HIV LTR Induction
With 250nM SAHA
Toxicity @ 48 Hours
CTG
HIV LTR Induction
Without SAHA
NFkB BLA Reporter
Counter Screen
~4,500 Compounds
Known HDAC Inhibitors
Known Farnesyl-Transferase Inhibitors
Compounds with unknown mechanism
17.4%
16.1%
66.5%
Data Analysis/
Hit Selection
Follow-up
Analysis
Testing interventions in vivo
LRAs
Immunodulators
HIV vaccines
Novel approaches
Reduction in:
ART
Baseline
• Leukapheresis for QVOA
and ca-HIV RNA
• SCA
• Immune assays
• Host cell assays & biomarkers
• Novel assays, eg. Quanterix
Simoa
After
*
intervention
• Leukapheresis for QVOA
and ca-HIV RNA
• SCA
• Immune assays
• Host cell assays & biomarkers
• Novel assays, eg. Quanterix
Simoa
• Resting CD4
cell infection
• Low-level
viremia
HIV DNA, RNA, antigen & viruses
HIV DNA
HIV RNA
in cells or culture
QVOA
Replicationcompetent
virus
Ho, Cell 2013
Ericksson, PLoS Path 2013
HIV Antigen
(protein)
detector
The “Real”
Reservoir
Persistent HIV infection despite ART
(per 106 cells)
Frequency
Time to eradication > 73.4 years
Viral
Activation &
Clearance
or Cell Death
100
10
1
0.1
0.01
-
Residual
Replication
or Cell
Proliferation
0.001
•0.0001
Given assay variance, a more than 6-fold RCI
decrease would have likelihood 0.023 (2.3%)
0.00001
• Therefore a measurable goal is therapy that can
0
1
2
3
4
5
reduce the latent reservoir
log
Timeby
onhalf
ART a(years)
6
7
al. JID 2016
2015
Margolis, Garcia, Hazuda,Crooks
HaynesetScience
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 hosttargeted, 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
1. Single-protein molecules are
captured and labeled on individual
beads using standard ELISA
reagents
Quanterix Simoa Platform
2. Beads + substrate are loaded in
individual femtoliter wells. Oil
added to seal well
3. Digital or analog
fluorescence readout of
individual beads
•
Ultrasensitive platform (sub-pg/mL sensitivity)
•
Full automation (samples in – data out)
– Rapid readout (~1 hr), >500 data points per day
http://www.quanterix.com/
•
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
Howell et al. submitted
Latency Clearance Assay
CD8+ by negative
selection
PBMCs
CD8+
Resting CD4+
cells by
negative
selection
Culture
Resting
CD4+
cells
Latency
Reversing
Agent
or
CD8+,
HXTCs
,
or
DARTs
or
No
Effectors
Limiting
Dilution
Co-culture
Add
Effectors
Remove
Effectors
Measure
HIV
Production
at 2 weeks
PHA
Number of positive wells
(out of 12 total)
HXTCs Reduce Recovery of Virus from autologous
resting CD4+ T cells stimulated with:
No Effectors
CD8
HXTC
8
7
6
5
†
4
††
3
2
††
†
1
0
Patient
423
Patient
250
Patient
231
Patient
492
Patient
532
Patient
425
VOR
% Viral recovery
Patient 425
120
†p<0.05 compared to No Effector
100
††p<0.05 compared to BOTH
80
60
††
†
40
††
20
0
Patient
425
Patient
532
Patient
250
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
Apologies, too many references to cite!
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 primatized
monoclonal 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
Targeting HIV Reservoir in Infected CD4 T cells by
DARTs that bind Envelope and Recruit CTLs. Sloan
DD et al. PLoS Pathogens, 2015
Sung et al.:
• Screened ADCC, non-neutralizing
Abs that bound HIV-infected CD4 T
cells for optimal ADCC
• Constructed DARTs with nonNeutralizing 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 nonneutralizing DARTs
• Best were PGT121, A32 and 7B2
DARTs
( n o r m a liz e d t o n o E f f e c t o r s c o n t r o l)
% v ir a l r e c o v e r y
HIVxCD3 DART Mediated Clearance of Resting
Patient CD4 Cells Exposed to Vorinostat
V O R - E x p o s e d L a t e n t ly In f e c t e d C e ll s
120
N o E ffe c to r s
100
C D 8 o n ly
C D 3x4420
80
C om bo D AR Ts
60
40
20
0
0
0
674
408
407
795
795
P a t ie n t
2 4 h r c u lt u r e w it h D A R T s
96hr
HIVxCD3 DART-mediated virus clearance in 4 of 4 patients (longer
time needed for Pt 795)
Sung, et al. JCI 2015
Latency Reversal and Clearance Candidates
• 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!
Apologies, too many references to cite!
Tools to Test Latency Reversal and
Clearance
Minimal effect of VOR on immune function
Clutton
Sci Rep 2016
Persistent LRA activity of multiple VOR doses
p < 0 .0 0 0 1
H IV - 1 g a g R N A c o p ie s p e r w e ll
Autologous DC vaccine
2500
2000
Archin
Keystone Symposium on
HIV Persistence 2016
1500
1000
500
0
Baseline
Multidose
Combination Latency Reversal and
Clearance Trial I
Step 1
Screen
Step 2
Enrollment
Step 3
Interval
Step 4
AGS
Approximately
~Week 10 - Week ~Week 15 Week 24
Weeks 0 - 8 ~Week 6 - Week 13
18
Visits 1&2
Visit 3 & 4
Vists 5 - 7
BASELINE
Step 5
AGS Dosing
Step 6
Multiple VOR Dosing
Step 7
AGS Dosing
Step 8
Multiple VOR Dosing
~ Week 27 - Week 46
~Week 39 - Week 54
~Week 52 - Week 73
~Week 64 - Week 81
~Week 73 Week 89
Visit 9 - 13
Visits 14 - 17
Visits 18 - 22
Visits 23 - 26
27
Visit 8
EOS
AGS Manufacturing
Single Dose
Paired Doses
Interval dosing X 10 doses
Injections X4
LRA x 1
EOS
Term
Interval dosing X 10 doses
Injections X4
LRA x 2
LRA x 10
Vaccine
visits - no dosing
Leukapheresis & rc-RNA
visits - Vorinistat doses
Safety labs
Vaccine
= Argos dendritic
cell therapy
visits - AGS-004 injections
PK Samples
measurement determines progress
LRA =rc-RNA
vorinostat
LRA x 10
Vaccine
IM and Proviral
SCA
Exploratory Immunology
Viral inhibition and latency clearance assays
Acetylation
Combination Latency Reversal and
Clearance Trial II
STEP 3:
HXTCs
produce
d
STEP 4: FirstSTEP
Combination
1
STEPREST
2: STEPSTEP
3: 5: First
STEPCombination
4: First Combination
STEP 6: Immune
REST Response
STEP 5:monitoring
First Combination
treatment Pretreatm
Single
PERIO HXTCs
treatment
treatment
PERIO
treatment
VOR every 72
enthours
Phase
x 10 VORD
produce
VOR every
VOR
72every
hours72
and
hours x 10
D
VOR every 72 hours and
doses and Exhibit Ex- 400mg
d 2 HXTC Infusions
doses and
2 HXTC Infusions
2 HXTC Infusions
vivo
dose
2 HXTC Infusions
response
to VOR
~4 weeks
~8
weeks
~6-8
weeks
4 weeks
Visits 1 2
3
6
7
8
9Visits
101 11
2
123
3.1
4 135 14 15
6 16
7 17
8 18
9 19
10
cART
VOR every 72 hours
x 10 doses
~45 weeks2-4
weeks
HXTC
ART
5
~8 2-4
~6-84 weeks 4 weeks
weeks
weeks weeks
HXTC
4
HXTC
3.1
~4 weeks
HXTC
STEP 2:
Single
VOR
400mg
dose
HXTC
STEP 1
Pretreatm
ent Phase
Exhibit Exvivo
response
to VOR
11 2012
21
22
4 weeks
13
23 14 15
24 16 25
17 18 19
cART
VOR every 72
VOR
hours
every 72 hours
x 10 doses x 10 doses
VOR every 72 hours
x 10 doses
Cath Bollard
Immune Response Assays
Immune
HXTC Infusion
Response
Assays
Leukapheresis
HXTC Infusion
Clio
Rooney
Leu
Steps to eliminate
HIV infection
Latency
Reversal
Finally: the addition of durable
vaccine protection if rebound or
reexposure occurs