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Antibody‐Targeted Vaccines Tibor Keler, PhD
Antibody‐Targeted Vaccines
Tibor Keler, PhD
Monoclonal Antibodies as Therapeutics
• Unconjugated mAbs: Passive vaccines
• Target the cancer or pathogen
or pathogenic molecule
• Conjugated mAbs: Toxin/radionuclide conjugates
• Target the cancer
• Antibody-targeted vaccines: Antigen conjugates• Target the immune system to
to respond to cancer or pathogen antigen
In vivo antigen DeliveryTargeting to endocytic receptors on DCs and other APCs
Antibody Specificity:
Fc receptorsC‐type lectinsComplement receptorsMHC
• Enhance efficacy of protein vaccines
• Improved cross‐presentation to CD8+ T cells
• Broad response to multiple epitopes
Antibody‐Targeted Vaccines
Recombinant fusion proteins
Chemical conjugation
IgG‐antigen
Fab‐antigen
Targeting C‐Type Lectin Receptors
DEC-205CD205MR
CD206
Triad of acidicamino acids
Cysteine rich repeat
Fibronectin domain
CRDs-carbohydraterecognition domains
Tyrosine -basedmotif for targeting
B11Hu IgG1
3G9Hu IgG1
Antibody Specificity APC Binding in human tissues AffinityKD (M)
B11 Mannose receptor
Dermal DCs, Interstitial DCs, macrophages in most tissues
~7 x 10‐10
3G9 DEC‐205 DCs in lymph nodes, tissue DCs ~2 x 10‐10
APC targeting
Vaccine Uptake by human DCs in vitro
Fluorescent labeledantigen
0 min0 min0 min
Fluorescent labeledanti-MR-antigen
fusion protein
0 oC 37 oC , 60 min.
Confocal microscopy images of human DCs
Targeted delivery to APCs in vivo
hMR‐TGWT
wt hMR‐tg
B11‐hCG10 g
Draining lymph nodestained for hCG
24hrs
Vaccine Uptake – in vivoRabbit hCG, 0.2 µg/mlRabbit hCG, 0.2 µg/ml
Rabbit hCG, 0.2 µg/ml
Skin punch‐biopsies taken from injection site and opposite arm‐
48 hrs post injection of 1mg B11‐hCG i.d.
IHC ‐ rabbit anti‐hCG
Injection site
Control arm
Cross‐Presentation
Cross‐presentation of MR‐targeted antigen
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
No Ag B11-OVA 1g
B11-OVA 10g
OT-I
OT-II
4.5% 3.1%
14.5% 2.2%
91.3% 3.3%
4.1% 6.7%
6.9% 3.4%
81.0% 5.2%
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
100
101
102
103
104FL1-H: CFSE
No Ag B11-OVA 1g
B11-OVA 10g
OT-I
OT-II
4.5% 3.1%
14.5% 2.2%
91.3% 3.3%
4.1% 6.7%
6.9% 3.4%
81.0% 5.2%
wt hMR‐tg B11‐OVA +/‐ CpG
OT‐I or OT‐II
Splenocytes analyzed forProliferation (day 3) & IFN‐(day5)
# IF
N-
Prod
ucin
g O
T-I c
ells
pe
r 105
sple
nocy
tes
No CpG With CpG
0
200
400
600
800
No A g B11-OV Afusion
No A g B 11-OV Afusion
W ThMR Tg+
# IF
N-
Prod
ucin
g O
T-I c
ells
pe
r 105
sple
nocy
tes
No CpG With CpG
0
200
400
600
800
No A g B11-OV Afusion
No A g B 11-OV Afusion
W ThMR Tg+
Raphael Clynes, Department of Medicine and Microbiology, Columbia University, NY
CD8CytotoxicT cells
CD4HelperT cells
Breadth of T cell response
Presentation of multiple NY‐ESO‐1 MHC II epitopes with ‐DEC‐205‐NY‐ESO‐1
#1 #2 #3 #4 #5 #6 #7 #8 #9 #10
#11
#12
#13
#14
#15
#16
#17
Unp
ulse
d
Num
ber o
f IFN
-sp
ots
0
200
400
600
800
peptide pool
3G9-NY-ESO-1
Presensitized with
NY-ESO-1 protein
0
100
200
300
400
500
600#1 #2 #3 #4 #5 #6 #7 #8 #9 #10
#11
#12
#13
#14
#15
#16
#17
Unp
ulse
d
peptide pool
3G9-NY-ESO-1
NY-ESO-1 protein
Presensitized with
Num
ber o
f IFN
-sp
ots
NY-ESO-1 Peptide
NY-ESO-1 Peptide
Stimulation of NY-ESO-1 CD4+ T cell responses from patient AS
Stimulation of NY-ESO-1 CD4+ T cell responses from patient VZ
Data from G. Ritter, Ludwig Institute for Cancer Research
Presentation of multiple NY‐ESO‐1 MHC I epitopes with ‐DEC‐205‐NY‐ESO‐1
-1401
1-20
11-3
0
21-4
0
31-5
0
41-6
0
51-7
0
61-8
0
71-9
0
81-1
00
91-1
10
101-
120
111-
130
119-
143
131-
150
139-
160
151-
170
161-
180
#1-1
7
Unp
ulse
d
Num
ber o
f IFN
-sp
ots
0
100
200
300
400
500
600
700
peptide pool3G9-NYESO-1
Presensitized with
Peptide 101-109/ HLA-B*4002
Peptide 124-133/ HLA-B*4002
Peptide 157-165/ HLA-A*0201
NY-ESO-1 peptide
Stimulation of NY-ESO-1 CD8+ T cell responses from patient SB
Data from G. Ritter, Ludwig Institute for Cancer Research
Translation to clinical studies
Clinical Vaccine Candidates
hCG ‐ ‐chain of human chorionic gonadotropin• expressed by various epithelial and germ cell tumors• expression correlates with poor outcome• implicated in protection of tumors from apoptosis• human CTLs efficiently recognize and kill cancer cell lines expressing hCG
B11
NY‐ESO‐1 – Cancer‐testis antigen• expressed by sarcomas, melanoma and other tumors• immunogenicity in humans well documented• Adoptive transfer of NY‐ESO‐1 specific T cells can lead to significant clinical regressions
3G9
CDXCDX‐‐13071307
CDXCDX‐‐14011401
CDX‐1307 (‐MR‐hCG) ‐ Clinical Trial DesignPhase 1 Study – Advanced breast, colorectal, and pancreatic cancers
2 weeks
GM‐CSF (s.c.)
CDX‐1307 (i.c.)
Poly ICLC (s.c.)R848 (topical)
CDX-1307 (Single agent)
0.3 mg
1.0 mg
2.5 mg
2.5 mg + GM-CSF
2.5 mg + GM-CSF + Poly ICLC
2.5 mg + GM-CSF + R848
2.5 mg + GM-CSF + Poly ICLC + R848
CDX-1307 (Adjuvant combinations) • 6 patients per cohort
• Safety assessment after 3 patients in each cohort
• No dose limiting toxicities
Summary of hCG‐‐specific humoral responses
Humoral responses to purified hCG were measured by ELISA. The values reported represents the maximum titer (reciprocal dilution) for each patient that received at least 3 doses of vaccine.
CDX-
1307
+
GM +
R84
8
Induction of hCG‐‐specific T cell responses
Cellular responses were measured by IFN‐ELISpot assay using T cells (CD4 and CD8) isolated from patient PBMCs after a 7‐day in vitro stimulation with hCG‐derived peptide pool. Values represent the highest hCG‐specific T cell response (with control peptide subtracted) for patients treated in combination with TLR agonists. Significant T cell responses were not observed in cohorts without TLR agonist.
Elevated hCG‐β Levels Correlate with Reduced Survival in Patients with Invasive (T2‐T4) Bladder Cancer
Normal hCG-β
Elevated hCG-β
Months post-treatment
% s
urvi
val
R. Iles 1996
Randomized (1:1), controlled trial (n=60) in hCG‐ expressing, muscle‐invasive bladder cancer
Up to 8 weeks
DIA
GN
OST
IC
BIO
PSY
* * * *
CDX-1307 VACCINE REGIMEN
At -3 and -1 week, then on days 21-22 of
each 28-day cycle
Monthly x 6(over 6 months)
Every 3 months x 2(over 6 months)
NEOADJUVANT CHEMOTHERAPY
4-6 weeks Follow up for Progression and Survival12 weeks (3 monthly cycles)
BLA
DD
ER
RES
ECTI
ON
Neoadjuvant setting allows for pathologic assessment of tumor response to therapy (necrosis, immune infiltration, persistence of hCG- expression). Outcome measures: PFS (primary), OS, safety, immune response (during neoadjuvant
chemo and adjuvant vaccine), tumor response (radiographic and pathologic)
Initial data anticipated late 2011 - 2012
PHASE 2 TRIAL IN BLADDER CANCER: The “N‐ABLE” Trial Neoadjuvant and Adjuvant Bladder Cancer Trial
hCGIHCPCR
Conclusions• Delivery of protein antigens to endocytic receptors on APCs
results in:– Robust humoral/celluar immunity– Requires concomitant administration of adjuvants
• Antibody‐targeted vaccines provide a practical approach to vaccines:– Based on well established antibody technology– Off‐the ‐shelf and not HLA specific– Can be used for multiple antigens
• Early clinical data demonstrate feasibilty, safety, and immunogenicity
Acknowledgements
Celldex TeamCelldex TeamClinical:Tom DavisBeth CrowleyMike YellinJennifer Green
Research:Henry MarshLiZhen HeLaura VitaleVenky RamakrishnaRuss HammondLarry Thomas
Clinical InvestigatorClinical Investigator(CDX‐1307 program)
Michael Morse ‐ Duke University Medical Center
Robert Chapman‐ Henry Ford HospitalDing Wang‐ Henry Ford Hospital
John Powderly ‐ Carolina BioOncology Institute
CollaboratorsCollaborators
Ralph Steinman – Rockefeller U.Michel Nussenzweig – Rockefeller U.Sarah Schlesinger – Rockefeller U.Raphael Clynes – Columbia U.Gerd Ritter – Ludwig Inst. Can. Res.Robert Seder‐ NIH
