combination immune checkpoint inhibitors for the...
TRANSCRIPT
Combination Immune Checkpoint Inhibitors for
the Treatment of Colon Carcinoma in Humanized
Mice
Joseph Murphy, PhD
Director of Science, R&D Oncology
CTLA-4
CD28
PD1
CD8/TCR
CD8 T effector
Anti-PD1
Anti-CTLA-4
Block PD1 and CTLA-4 signaling in T effector and Tregs:
• Prevent T effector cell exhaustion and death
• Decrease Treg activity and proliferation
• Induction of Treg death by ADCC
• Create a favorable CD8 T-effector:T reg ratio
Effects of PD1 and CTLA-4 Signaling
ADCC/macrophage
Anti-CTLA-4
Tumor
Lck
ZAP70
class I
PI3K Akt
CD28
TCR
CD4
CTLA-4
Treg
PD-L1
Tumor cell
CD80/86
APC
PD-L2
SHP2
PP2a
SHP2
Two Platforms Available:
- CD34+ Embryonic Cell Engrafted (Jackson Lab)
- PBMC Engrafted
huCD34 model
- Week 3: huCD34+ HSC (~3x104)
- Umbilical cord blood
- Week ~15: >25% huCD45 in blood
- Long term studies
huPBMC model
- huPBMC injected (30x106)
- Week 3: ~30% huCD45 blood cells
- Short term studies
- T cell focused
- GVHD appears
huPBMC
Myeloablation (1 Gy)
huCD34
Cell line % CD80 + % CD86 + % CTLA-4 + % PD-L1 + % PD-L2 +
A375 0.0 0.0 0.0 66.8 0.0
HT-1080 0.0 0.0 0.0 98.2 0.4
SK-MEL-5 0.0 0.0 0.0 9.9 0.0
HCC827 0.0 0.0 0.0 94.8 0.6
Colo205 0.0 0.0 0.0 40.8 0.0
SK-MEL-24 0.0 0.0 0.0 8.4 0.0
RKO 0.0 0.0 0.1 99.9 22.0
MDA-MB-231 0.0 0.0 0.1 99.7 0.7
HCT116 0.1 0.0 0.0 60.5 0.0
Calu6 1.2 0.0 0.0 53.8 0.0
SKOV3 0.0 0.0 0.0 73.1 0.8
ME-006 0.0 0.0 0.9 86.5 5.7
ME-012 0.0 0.0 0.0 15.4 0.4
ME-016 0.0 0.0 0.2 7.6 0.0
TH-005 0.0 0.0 0.4 98.3 9.3
NS-036 0.0 0.0 0.0 80.9 1.5
A2058 0.0 0.0 1.1 55.0 0.6
% subtracted from Isotype Control
Evaluation of the Expression of PD-L1, PD-L2, CTLA-4,
CD80 and CD86 in human tumor cell lines and PDX
CD34+ Cell Engrafted Studies - RKO Colon Tumor Implant (High PD-L1 Expression)
- HLA-A*01/01 matched
- Treatment with Ipilimumab and/or Pembrolizumab
Exp. I Exp. II
Initial Assessment of human immune cell engraftment
Percentages of hCD45 and mCD45 populations were
calculated relative to the live cell gate in individual samples.
Percentages of hCD3 and mCD3 (top) were calculated relative
to hCD45 and mCD45. hCD4 and hCD8 (bottom) populations
were calculated relative to hCD3 cells in individual samples.
CD34+ NSG mice engrafted studies: Exp. I and Exp. II
Control IgG 200mg biwk x3
Ipi 100mg biwk x3
Pembro 100mg biwk x3
Ipi + Pembro
Non-engrafted - NOG
RKO-e210 blood sample for human immune cells day 15
p<0.02
p<0.004 p<0.02
p<0.03
RKO-e210 blood sample for human immune cells day 15
p<0.02
CD45RO
CC
R7
Effector
Central
Memory
Effector
Memory
Naive
Control
Gate on CD8+ cells
CD45RO
CC
R7
Effector
Central
Memory
Effector
Memory
Naive
Ipi+Pembro
Gate on CD8+ cells
p<0.002
p<0.02
p<0.02
Distribution of T cell subsets
RKO-e210 tumor response to immune checkpoint
inhibitors day 15
RKO-e210 human immune TILs at day 15
p<0.02
p<0.005
p<0.002
CD34+ NOG mice Non-HLA-A matched + Pembrolizumab
RKO-e219
HLA-A matched Non HLA-A matched
Summary and conclusions
• Pembrolizumab and ipilimumab monotherapies significantly inhibit tumor growth in
human RKO colon carcinoma xenograft in the CD34+ NSG humanized mouse model.
• Combination therapy does not enhance the efficacy demonstrated by either
monotherapy.
• Activated effector T cells appear to play a role in tumor rejection
• mMDSC, gMDSC and macrophages poorly represented in this model (data not
shown).
Questions?
Call with questions: 1-877-274-8371
www.criver.com