Post on 18-Dec-2015
CLL
Stromal cell
protect
Conventional therapies
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The “outside” (microenvironment) of the CLL cell: new insights into disease
biology and new therapeutic targets
Jan Burger, MD PhD
Department of Leukemia
MD Anderson Cancer Center
Microenvironment in CLL Larger proliferating CLL
cells form proliferation centers (pseudofollicles), a hallmark finding in CLL
Within pseudofollicles, CLL cells are in close contact with accessory cell (stomal cells, T cells)
From: Soma LA et al, Human Pathology. 2006;37:152-159
From: PE Patten et al. Blood. 2008;111:5173-81
Messmer BT, et al.
J Clin Invest. 115(3): 755-764, 03/2005
Microenvironment in CLL: a-SMA and CD14/68+ cells
From: J Rual et al. Clinical Cancer Research 12, 5622-31, 2006
Bh
att
ach
ary
a a
nd
Me
rte
ns
et
al.,
Le
uke
mia
(2
011
) 2
5,
72
2–
72
6
CLL#1
CLL#2
CLL#3
normaltonsil
CLL in vitro model: BMSC co-cultures
• Standardized CLL-stroma co-culture conditions for drug testing
• Ideal for testing drug combinations
Fro
m:
Siv
ina
et a
l., L
euke
mia
26:
1812
-20,
08/
2012
IN VITRO MODEL : Nurselike cells
CXCR4†
CXCL12CXCL13CXCR5¶
CD31, plexin-B1
CD38, CD100‡
BAFF, APRIL
BAFF-R, BCMA, TACI*
* Nishio M et al. Blood 106:1012-20, 2005¶ Burkle A et al. Blood 110:3316-25, 2007
† Burger JA et al. Blood 96, 2655-63, 2000‡ Deaglio S et al. Blood 105(8):3042-50, 2005
# Burger JA et al. Blood. 113:3050-8, 2009
?antigen
BCR#
The lymph node microenvironment promotes BCR signaling
CLL cells isolated from lymph nodes showed upregulation of CCL3 and CCL4
LN signature GEPs have a remarkable similarity to GEP of CLL cells after co-cultured with nurselike cells, including upregulation of CCL3, CCL4, EGR2, EGR3, and MYC
From: Y Herishanu et al., Blood. 2011 Jan 13;117(2):563-74
CCL3
CCL4
Summary: molecular interactions in the CLL microenvironment
The moleculoar interactions between CLL cells and their microenvironment are complex
Soluble factors, BCR signaling and cell-cell interactions are important
Chemokine receptors and BCR-associated kinases are current drug targets
From: Burger JA et al., Blood. 2009 Oct 15;114(16):3367-75
Targeting the microenvironment in CLL: Plerixafor (AMD3100)
Plerixafor is a CXCR4 antagonist and blocks HIV-1 entry into T cells
Plerixafor is a bicyclam Plerixafor binds to Asp171
in TM-IV and Asp262 in TM-VI of CXCR4
From: Gerlach LE et al., J. Biol. Chem. 276:14153, 2001
Results: Best Confirmed Response*
0.08 mg/kg
n=3
0.16 mg/kg
n=4
0.24 mg/kg
n=3
0.32 mg/kg
n=7
0.42 mg/kg
n=4
Overalln=21
No. of Evaluable Patients 3 3 2 7 3 18
Evaluable patients with, n (%):
Complete ResponsePartial Response (PR)Stable Disease (SD)Progressive DiseaseRelapsed DiseaseTreatment Failure
02 (67)
01 (33)
00
000
3 (100)00
000
2 (100)00
04 (57)2 (29)1 (14)
00
02 (67)
000
1 (33)
0 8 (44)2 (11)7 (39)
01 (6)
* Responses were assessed based on definitions provided by the National Cancer Institute-sponsored Working Group guidelines for chronic lymphocytic leukemia. Cheson BD, et al; Blood. 1996 Jun 15;87(12):4990-7.
Targeting of BCR signaling in CLL
• BCR-associated kinases are targets of new drugs in preclinical and clinical development
• SYK (Spleen tyrosine kinase) inhibitors: fostamatinib (R788)
• BTK (Bruton’s tyrosine kinase) inhibitors: ibrutinib (formerly: PCI-32765)
• PI3 kinases: Isoform-Selective Inhibitor of PI 3-Kinases, GS-110 (formerly: CAL-101)
From: Nat Rev Immunol 2:945
Pattern of Response: Blood Lymphocytes vs Lymph Nodes
12
Mea
n %
Cha
nge
from
Bas
elin
e
Cycle
ALCSPD
SCR(61) 1(60) 2(57) 3(52) 4(50) 5(51) 6(47) 7(46) 8(48) 9(43) 10(38) 11(31)
SPD- sum of products of lymph node dimension
Inhibition of chemotaxisCXCL12 CXCL13
Ctrl
PCI-327
65 (1
0 nM
)
PCI-327
65 (1
00 n
M)
PCI-327
65 (1
000
nM)
Mig
rate
d c
ells
(%
of i
np
ut)
means of 6 patients ± SEM, *p≤0.05 compared to Medium
Med
ium
AMD31
00
**
+ chemokine
Med
iumCtrl
+ chemokine
**
PCI-327
65 (1
0 nM
)
PCI-327
65 (1
00 n
M)
PCI-327
65 (1
000
nM)
S. Ponader et al., Blood 119: 1182-9, 2012
GS-1101 (CAL-101) inhibits CLL cell chemotaxis towards CXCL12 and CXCL13
Hoellenriegel J et al.; Blood 118(13):3603-12, 09/2011
GS-1101 (CAL-101) antagonizes CLL cell migration beneath marrow stroma cells (pseudoemperipolesis)
Hoellenriegel J et al.; Blood 118(13):3603-12, 09/2011
PCI-32765: effects on adhesion and migration
From: Rooij et al., Blood 119: 2590-2594, 2012
VCAM-1adhesion assay
Chemotaxisassay
TCL1 MOUSE MODEL OF CLLEFFECTS OF BTK INHIBITOR IBRUTINIB
Vehicle control Ibrutinib 25mg/kg/day
0
10
20
Ctrl(n=4) 2.5
(n=3)25
(n=4)25
(n=4)Outliers
Bo
dy
we
igh
t (g
)
Ibrutinib (mg/kg/day)
P=0.356
P=0.13730 P=0.028
2.5 mg/kg/d 25mg/kg/day
Control + Ibrutinib
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6S
ple
en
we
igh
t (g
)P=0.64
P=0.05P=0.01
Ctrl(n=4) 2.5
(n=3)25
(n=4)25
(n=4)Outliers
Ibrutinib (mg/kg/day)
S. Ponader et al., Blood 119: 1182-9, 2012
BCR-RELATED BIOMARKER:CCL3, CCL4 (MIP-1α,β)
CCL3
CCL4
pg/
mL
time (days)
pre-treatment
S. Ponader et al., Blood 119: 1182-9, 2012
pre-treatment
Ibrutinib trial
GS-1101 trial
Hoellenriegel J et al.; Blood 118(13):3603-12, 09/2011
Key effects of inhibitors of BCR-associated kinases Btk, Syk, PI3Kδ
Inhibitors of BCR signaling and block survival and proliferation,
but also homing and tissue retention of CLL cells
Effects on either pathway differ between patients
Adapted after: Burger JA et al., Blood. 2009 Oct 15;114(16):3367-75
Summary and outlook
Chemokine receptors and adhesion molecules are essential for tissue homing and migration of CLL cells
CXCR4 and BCR-associated kinases (SYK, BTK, PI3Kδ) are targeted in clinical trials in CLL
These therapies “mobilize” CLL cells from the tissues into the blood
There is promising clinical activity of these new therapeutic approaches