Stem Cell Mobilization
Standards of Care for HSCT
Novel Applications
Richard Champlin, M.D.
Why is the bone marrow in the bone
marrow?
 Hematopoietic stem cells home to a “niche” in the
marrow
 Marrow microenvironment provides critical interactions
controlling the growth and differentiation of
hematopoietic cells
 Maturing cells naturally egress the bone marrow into
the blood and later into the tissues
 Stem cells traffic into and out of the bone marrow
physiologically
Stem Cell Niche
Bone Marrow Stromal
Microenvironment
CXCR4
SDF1
HSC
VLA-4
VCAM-1
Osteoblasts
Pamela S, et al. ASH 2008. Abstract #: 858;
Shivtiel et al. J Exp Med. 2008;205:2381.
Mechanisms Governing Stem Cell
Mobilization with G-CSF
Adhesive interactions
between HSC and matrix
components in the BM
G-CSF Mobilization
Cathepsin G (CG), chemokine receptor-4 (CXCR4), hematopoieic stem cell (HSC), hyaluronic acid (HA), interleukin 8 (IL-8), kit ligand (KL), matrix metalloproteinase9 (MMP-9), neutrophil elastase (NE), stromal cell derived factor-1 (SDF-1), vascular cell adhesion molecule-1 (VCAM-1), very late
antigen-4 (VLA-4), P-selectin glycoprotein ligand-1 (PSGL). Source: Nervi B, et al. J Cell Biochem. 2006;99:690-705
Considerations for Mobilization Regimen
• Reliable
•
Collect sufficient number of HSCs and progenitors
• Predictable
•
Able to predict day of collection
• Low failure rate
• Limited toxicity
• Cost Effective
Limited number of days of apheresis required
• Low resource utilization
•
• Low tumor contamination
Agents for
Stem Cell Mobilization
Plerixafor
G-CSF
SDF1
D11-5908
CXCR4
PP2 scr
inhibitor
Bone Marrow Stromal
Microenvironment
SDF1
HSC
VLA-4
MM9
VCAM-1
Fibronectin
Scr kinase
Osteoblasts
G-CSF
Pamela S, et al. ASH 2008. Abstract #: 858;
Shivtiel et al. J Exp Med. 2008;205:2381.
CD34+ Cells Are Heterogenous
CD34+
CD34+/CD61+
CD34+/CD38-
CD34+/CD61-
CD34+/CD133+
CD34+/CD133-
CD34+/HLA-DR+
CD34+/HLA-DR-
CD34+/CD38- = Most Primitive Stem Cells
Hock H. J Exp Med. 2010;207:1127-1130
When to Collect?
Correlation between PB CD34+ cells/µL and CD34+ cells/kg collection
Armitage S, et al. Bone Marrow Transplant. 1997;20:587-591.
How Many HSCT do you
need for AutoSCT?
Richard Champlin, MD
Platelet Engraftment Kinetics As
A Function Of CD34+ Cell Dose
Probability of Engraftment of Platelets ≥ 20 x 109/L
1.0
N = 212
0.9
0.8
0.7
0.6
0.5
0.4
CD34+ Cells x 106/kg
0.3
1.0
2.0
5.0
10.0
0.2
0.1
0.0
7
14
28
Days
Glaspy JA, et al. Blood. 1997;90(8):2939-2951.
28
Importance of CD34+
Cell Dose
Percent Patient Platelet Count > 150,000/L
CD34+ Cell Dose
Transplanted
Non-Hodgkin
Lymphoma
At 12 months
Multiple Myeloma
At 12 months
Stiff PJ, et al. Blood. 2008;112:758-759. Abstract 2175.
2-4
x 106/kg
≥ 4-6
x 106/kg
>6
x 106/kg
N = 76
N = 75
N = 66
56%
81%
83%
N = 75
N = 82
N = 64
74%
83%
81%
P
value
0.020
0.435
Defining a Target?
 Generally accepted that ≥ 2 x 106 CD34+ cells/kg is ensures
a threshold effect for a rapid hematopoietic
engraftment1-2
 95% of patients receiving > 2.5 x 106 CD34+ cells/kg
experience durable neutrophil engraftment by day 18
 5 x 106/kg may be threshold for rapid platelet
engraftment3-4
 Unclear if > 5 x 106/kg will result in any better
engraftment, may be associated with improved
outcome5
1To LB,
et al. Blood. 1997;89:2233-58; 2Schiller G, et al. Blood. 1995;86:390-7; 3Kiss JE, et al. Bone Marrow Transplant. 1997;19:303–10;
CH, et al. Blood 1995;86:3961–9; 5Dercksen MW, et al. J Clin Oncol. 1995;13:1922–32.
4Weaver
Higher Cell Dose: Impact on Cost
 Costs of transplant-related care in patients who
experience “good” versus “poor” mobilization
 Retrospective analysis of 172 NHL patients treated with HDT and
autologous PBSC transplantation
 Mobilizations categorized as “poor” (<2 ×106 CD34+ cells/kg) or
“good” (≥2 ×106 CD34+ cells/kg)
 Cyclophosphamide + G-CSF used for mobilization
 Cost data in a subset of patients (n=57)
“Good”
“Poor”
Mobilization Mobilization
Total costa
P Value
$80,833
$140,264
<0.001
Transplantation LOS, d
16
24.5
0.02
Total LOS, d
19
30.5
0.02
Stockerl-Goldstein KE, et al. Biol Blood Marrow Transplant. 2000;6(5):506-512.
a Includes
cost of apheresis and bone marrow harvest, if performed.
How to collect HSCT
 Chemo-Mobilization
 Integrates collection into
disease management
 Improves CD34 yield
 Cost, complications, can’t
predict date of collection
 Growth Factor
Mobilization
 Simple
 Efficient, can schedule
 Provides adequate CD34
yield in many categories of
patients
 Less Costly, few
complications, can predict
date of collection
 We use this for aggressive
lymphoma
 May interrupt/delay
chemotherapy
 We use this for myeloma
Factors Affecting CD34+ Cell Yield
Patient-related
 Age
 Mobilization regimen chosen
 Generally higher CD34 yields with chemo-based
mobilization
 Amount and type of prior therapy
 Alkylators, lenalidomide, radiation
 Platelet count at the time of mobilization
G-CSF vs Chemotherapy + G-CSF
Disease
State(s)
Study
Alegre A, et al.1
MM
Desikan KR, et al.2
MM
Dazzi C, et al.3
NHL
Narayanasami U, et al.4
NHL, HD
Pusic I, et al.5
NHL, MM,
HD
N
Mobilization
Regimen
Median Total
Collected CD34+
Cells X 106/kg
(Range)
Median
Apheresis
Sessions
(Range)
Number of
Mobilization
Failures
22
G-CSF
4.85 (2.1–10.1)
3 (2–6)
NR
18
Cy+GM-CSF
6.8 (1.8–34.8)
5 (4–12)
NR
22
G-CSF
5.8 (NR)
5
23%
22
Cy+G-CSF
33.4 (NR)
7
18%
12
G-CSF
2.89 (1.7–5.6)
16 total
NR
12
Cy+G-CSF
6.41 (2.2–25.9)
15 total
NR
22
G-CSF
2.5 (0.3–12.4)
NR (1–3)
1
24
Cy+G-CSF
7.2 (0.3–44.8)
NR (1–3)
1
976
G-CSF
3.36 (NR)
2 (1–5)
182
64
Chemo+G-CSF
5.43 (NR)
1.5 (1–5)
12
Chemo = various chemotherapeutic agents; Cy = cyclophosphamide; HD = Hodgkin's disease; MM = multiple myeloma;
NHL = non-Hodgkin's lymphoma; NR = not reported.
1Alegre
A, et al. Bone Marrow Transplant. 1997;20:211–217; 2Desikan KR, et al. J Clin Oncol. 1998;16:1547–1553; 3Dazzi C, et al. Leuk Lymphoma. 2000;39:301–310;
al. Blood. 2001;98:2059–2064; 5Pusic I, et al. Biol Blood Marrow Transplant 2008;14:1045–1056.
4Narayanasami U, et
Rituximab and HSC MobilizationMDACC Experience
 Rituximab reduces circulating lymphoma cells
 No impact on HSC mobilization, particularly with
chemomobilization
 Improvement in results of autoSCT using Rituximab in
mobilization and transplant.
ASCT for Aggressive NHL
Impact of Rituximab on DFS
Cumulative Proportion Surviving
1.0
p = 0.004
0.9
Rituximab (N=67)
0.8
0.7
0.6
0.5
No Rituximab (N=30)
0.4
0.3
0.2
0.1
0.0
0
3
6
9
12
15
18
Months Post Transplant
21
24
27
30
Adhesion Molecules And
HSC Mobilization
Mobilization
Plerixafor
Natalizumab
BIO5192
Nervi B, et al. J Cell Biochem. 2006;99:690-705.
Plerixafor
 A sustained elevation of peripheral blood CD34+ cell levels was noted
between 4 and 18 hours1
250
200
150
100
50
n = 3 healthy volunteers
0
0
5
10
15
20
Time (hours) calculated after 4 days of G-CSF therapy and addition of GCSF + Mozobil™ (plerixafor injection) on day 5
G-CSF, granulocyte-colony stimulating factor.
1. Mozobil™ [prescribing information]. Cambridge, MA: Genzyme Corp; 2008. 2. Adapted from Liles WC, et al. Transfusion. 2005;
45:295-300.
20
Mobilization Using
G-CSF With Plerixafor
 Efficacy as single agent
 Synergistic with G-CSF
 Increases likelihood of successful CD34+ cell mobilization
 QUESTIONS:
 Are there important functional differences in the grafts collected?
 Are the improvements in CD34 yield worth the added cost?
 Effect on mobilization of malignant cells?
Gene Expression of Mobilized CD34+ Cells
and Leukocytes
Gene expression differs among
CD34 cells mobilized plerixafor,
G-CSF, and plerixafor + G-CSF
1. Composition of mobilized CD34+ cells
is dependent on the mobilization
protocol
2. Composition of CD34+ cells mobilized
by the combination is not simply a
mixture of cells mobilized by each
agent separately
Donahue RE, et al. Blood. 2009;114:2530-2541.
Functional Differences Noted With Plerixafor
vs G-CSF-Mobilized HSPCs
 Higher proportion of cells in G1 phase of the cell cycle
 Higher proportion of more ‘primitive’ CD34+CD38-
cells
 More cells expressing CXCR4 and VLA-4 on the cell
surface
 Grafts contain more T, B and NK cells
Larochelle A, et al. Blood. 2006; 107:3772–3778; Hess DA, et al. Biol Blood Marrow Transplant. 2007; 13:398–411;
Fruehauf S, et al. Cytotherapy. 2009; 11:992–1001; Donahue RE, et al. Blood. 2009; 114:2530–2541;
Plerixafor vs G-CSF-Based Stem Cell Mobilization in
HLA-Identical Donors: Allograft Composition
Plerixafor
G-CSF‡
1.4
1.0
8
27
0.001
CD34 (x106/kg)†
2.9 (1.2-6.3)
4.2 (2.5-18.7)
0.006
CD3 (x108/kg)†
4.6 (1.5-7.8)
1.3 (1.2-6.8)
0.006
CD4 (x108/kg)†
3.2 (1.0-5.7)
1.1 (0.7-3.2)
0.002
CD8 (X108/kg)†
1.3 (0.4-3.4)
0.4 (0.3-3.4)
0.08
CD56 (x107/kg)†
3.0 (1.0-10.0)
2.0 (1.0-5.0)
0.2
No. of Apheresis Attempts*
Peak Fold in CD34 Count*
*Mean.
†Median.
‡Includes 8 donors mobilized by both plerixafor and G-CSF.
Devine S, et al. Blood. 2008;112(4):990-998.
P Value
Cancer Cell Mobilization in Autologous
Donors???
CXCR4 Antagonist
CXCR4 / SDF-1
? Release of
Tumor Cells
Gazitt Y. Leukemia. 2004;18;1-10.
Apheresis Costs
Treatment Phase
Cost
Pre-apheresis
Clinic visit
Lab evaluation
Insertion of CVC
Chest –x-ray
Apheresis
Apheresis procedure (2)
G-CSF treatment (2)
CD34+ analysis
Post-apheresis
Cryopreservation
Supplies
Storage
Sterility testing
Total Cost*
Cost Savings of Eliminating
One Day of Apheresis*,#
$1,800
$5,161
($2,580.7 per day)
$2,493
($1,246 per bag)
$9,454
$3,826
Hosing et al
MDACC Policy PBPC Collection
 For autos and allos- goal 5 million, accept minimum 2
million CD34/kg,

Day 1 or 2 stop >4M

Day 3 stop >3M

Day >4 stop >2M
 Collect If CD34 > 10/mcl
 If collection is ≤ 0.3 million/kg/d x 2 consecutive days
despite use of plerixafor or stop apheresis
Myeloma- plan for 2 transplants
 Target doses: Goal 6-8 million/kg for 2 transplants (minimum
acceptable 4 million/kg)
 If after 1 or 2 collections CD34 collected is > 8 million/kg stop
 If after 3 collections CD34 collected is > 6 million/kg stop
 If after 4 collections CD34 collected > 4 million/kg stop
 If after 5 collections CD34 collected > 2 million/kg stop, do
one transplant
Just In Time Strategy for Cost
Effectiveness
 G-CSF alone successfully mobilizes many patients
 Plerixafor is synergistic with G-CSF for stem cell
mobilization
 An approach to improving cost effectiveness is
reserving plerixafor for patients with suboptimal
mobilization
 Use circulating CD34 on day 4 or first day’s collection to
determine who needs addition of plerixafor.
Factors Associated With
Poor Mobilization
 Increasing cycles /
duration of prior
chemotherapy
 Female gender
 Prior radiation to bone
marrow
 Low pre-mobilization
platelet count
 Bone marrow positivity
 Indolent lymphoma
histology
 Exposure to fludarabine,
platinum-based
chemotherapy, alkylating
agents, lenalidomide
 Low PB CD34 count during
mobilization
Outcome of Mobilization by Disease
Disease
Hodgkin
N = 93
NHL
N = 685
MM
N = 997
Optimal
≥ 5 x 106 CD34+ cells/kg
40
199
699
Low
≥ 2-< 5 x 106 CD34+ cells/kg
28
262
162
Poor
< 2 x 106 CD34+ cells/kg
8
119
48
Failed
PB CD34 < 10/µL
Gertz M, et al. Bone Marrow Transplant. 2010 Jan 11. epub.
27%
17
33%
105
14%
88
Percent ≥ 2 Million CD34+ Cells/kg
Phase III NHL Study
Kaplan-Meier estimate of proportion of
patients reaching ≥ 2 x 106 CD34+ cells/kg
HR=2.50, 95%CI (1.86, 3.36), p<0.0001
DiPersio JF, et al. J Clin Oncol. 2009;27:4767-4773.
Plerixafor +G-CSF
Placebo + G-CSF
Conclusions
 Hematopoietic stem and progenitor cells are mobilized by G-CSF and
plerixafor a CXCR4 inhibitor
 Plerixafor mobilizes PBPC by inhibition of SDF-1 and CXCR4 interaction
 Plerixafor and G-CSF are synergistic
 The combination of Plerixafor and G-CSF will reduce the number of
aphereses required for PBPC collection and enhance to ability to perform
autologous HSCT in “hard to mobilize” patients
 Chemotherapy plus growth factor enhances mobilization and is
warranted when the chemotherapy is indicated for treatment of the
malignancy