Antagonist Anti-CD40 Antibody CHIR-12.12 Inhibits
Tumor Growth and Prolongs Survival in Human
Multiple Myeloma Xenograft Models
Li Long, Xia Tong, Montesa Patawaran, Lea Aukerman, Bahija Jallal and
Mohammad Luqman
BioPharma Research, Chiron Corporation, Emeryville, California, USA
April 14th, 2005
In partnership with
CD40 and B-Cell Malignancies
· A type 1 membrane protein of 48 kD MW, member of TNF
receptor superfamily.
· Expressed on all types of malignant B-cells, and normal
B-cells, dendritic cells, monocytes and macrophages.
· Effects of CD40 activation in normal and primary
malignant B-cells:
- Cell survival (protection from apoptosis)
- Cell proliferation
- Upregulation of adhesion molecules
- Cytokine production
- Resistance to chemotherapy (in malignant B cells)
2
CD40 and Multiple Myeloma
· CD40 is expressed in >80% of patients - variable levels
· CD40 stimulation by CD40L:
- Prolongs survival of patient MM cells
- Promotes secretion of IL-6 and VEGF by MM cells/bone marrow stromal
cells (BMSC)
- Enhances adhesion of MM cells to BMSC
- Enhances MM cell migration
Tai and Anderson et al. Blood 2004; 104: 663a #2414
An antagonistic anti-CD40 mAb should block these activities
3
Human anti-CD40 mAb CHIR-12.12
· Fully human, IgG (Abgenix XenoMiceTM)
1
· Antagonist antibody
- Blocks CD40L binding and can compete off pre-bound CD40L
- Inhibits CD40L mediated normal & neoplastic B cell proliferation/survival
- Does not stimulate proliferation or survival of normal or malignant B cells
- Does not induce CD40-mediated signaling
· Mediates potent ADCC
- High binding affinity
- Slow off-rate
- Not internalized
Two mechanisms of action:
· Blocking CD40 signaling
· Mediating ADCC
4
CHIR-12.12 Potently Inhibits CD40L-Induced
Human B Lymphocyte Proliferation
30000
IC : 47±21 pM (N=6 Normal doners)
50
(CPM) 25000
20000
15000
Incorporation
10000
midine
5000
H]Thy3[
06 5 4 3 2 1 0
Log [CHIR-12.12] (µg/mL)
5
CHIR-12.12 Mediates Potent ADCC Activity
Against Multiple Myeloma Cell Lines
KMS-12-BM
IM-9
ARH-77
25
70
60
20
s
60
50
EC =17.9 pM
EC =5.9 pM
EC =23.9 pM
50
50
50
ysi 15
l
50
40
fic 10
40
30
5
speci
30
20
%
0
20
10
-5
10
0
-8
-7
-6
-5
-4
-3
-2
-1
0
1
-8
-7
-6
-5
-4
-3
-2
-1
0
1
-7
-6
-5
-4
-3
-2
-1
0
1
Log [CHIR-12.12] (µg/ml)
6
CHIR-12.12 Prolongs Survival in the Unstaged
Orthotopic (i.v.) IM-9 Xenograft Model
110
)
100
l(%
90
Control IgG1, 10 mg/kg
a
80
iv
CHIR-12.12, 0.1 mg/kg
rv
70
CHIR-12.12, 1 mg/kg
u
60
lS
50
CHIR-12.12, 10 mg/kg
an 40
bortezomib, 0.5 mg/kg
30
itio
bortezomib, 1 mg/kg
d
20
no 10
C
0
0
10
20
30
40
50
60
70
80
90 100 110
bortezomib administration
Days after tumor implantation
Antibody administration
CHIR-12.12 administered i.p. once a week for 4 weeks. Bortezomib administered i.v. twice a week for 2 weeks.
7
CHIR-12.12 Prolongs Survival in a Staged
Orthotopic (i.v.) IM-9 Xenograft Model
120
) 100
%(
Control IgG1, 1 mg/kg
aliv 80
CHIR-12.12, 0.1 mg/kg
v
CHIR-12.12, 1 mg/kg
Sur
60
CHIR-12.12, 10 mg/kg
tional
40
bortezomib, 0.5 mg/kg
Condi
20
0
0
15
20
25
30
35
40
Days after tumor implantation
· Administration of therapeutics begins 7 days after tumor cell implantation.
· CHIR-12.12 administered i.p. once a week for 4 weeks. Bortezomib administered i.v. twice a week for 2 weeks.
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CHIR-12.12 Reduces Cellular Proliferation and Induces Cell
Death in IM-9 Xenograft Model
Control IgG1 10 mg/kg, i.p. x 1, Day 5
Ki-67
cCaspase 3
cPARP
CHIR-12.12 10 mg/kg, i.p. x 1, Day 5
Ki-67
cCaspase 3
cPARP
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CHIR-12.12 Inhibits the Growth of Human
KMS-12-BM Subcutaneous Xenograft Model
2000
Control IgG1 1 mg/kg
ean
1500
bortezomib 0.5 mg/kg
M(
CHIR-12.12 1 mg/kg
meu SEM)± 1000
CHIR-12.12 10 mg/kg
3
vol
or
mm
500
bortezomib dosing
Tum
Antibody dosing
0
15
20
25
30
35
40
45
Days post tumor implantation
CHIR-12.12 administered i.p. once a week for 4 weeks. Bortezomib administered i.v. twice a week for 2 weeks.
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Conclusions
· CHIR-12.12 is a potent antagonistic anti-CD40 monoclonal antibody.
- Blocks CD40L induced proliferation and survival of normal and neoplastic
B cells
- Mediates ADCC activity against MM cell lines with picomolar EC50
- Inhibits CD40L-stimulated survival of patient MM cells, IL-6 and VEGF
secretion and MM cell adhesion to FN and BMSCs (Tai & Anderson et al.
Blood 2004; 104: 663a #2414)
· CHIR-12.12 exhibits significant anti-MM activity in bortezomib
insensitive xenograft models:
- Orthotopic and subcutaneous
- Staged and unstaged
- Multiple CD40+ human tumor xenograft models
· CHIR-12.12 is currently in a phase I clinical trial for CLL and a phase I
clinical trial for MM is planned in 2005.
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