AMD3100 for Stem Cell Mobilization in Normal Donors

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AMD3100 for Stem Cell Mobilization in Normal
Donors

• Steven Devine
• Washington University School of Medicine

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Considerations for Graft Selection

• Differences in quantity/quality of HSC from
  various sources
• Differences in accessory cell populations among
  graft sources
• Dendritic cells
• T-cells
• Stromal cells?
• Requirement for Graft Manipulation
• Donor source (related/unrelated)

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Kinetics of CD34 mobilization G-CSF and GM-CSF
G-CSF
GM-CSF
Fischmeister et al, Ann Hematol, 1999
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Allograft Content MPB versus Bone Marrow
Korbling and Anderlini, Blood, 2001
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Allograft Content MPB versus Bone Marrow
Korbling and Anderlini, Blood, 2001
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Randomized Trials Comparing Peripheral Blood to
Bone Marrow
Devine et al, J Lab Clin Med, 2003
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Results with G-CSF mobilized HLA-identical
Peripheral Blood

• More rapid hematopoietic reconstitution
• Less early mortality in high risk patients
• No improved survival in good risk patients
• Slight overall survival advantage in high risk
  patients
• Higher rates of late GVHD-related complications
• Associated with worse survival in two
  retrospective IBMTR analyses
• childhood leukemias
• aplastic anemia
• Less toxicity to donors?

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Influence of graft content on clinical results

• Higher CD34 doses associated with greater risk of
  acute GVHD
• Przepiorka et al, Blood, 1999
• Urbano-Ispizua, Blood, 2001
• Higher CD34 doses associated with greater risk of
  chronic GVHD
• Przepiorka et al, Blood, 2001
• Zaucha et al, Blood, 2001
• Not all studies are in agreement

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What is the optimal MPB allograft composition?

• Doses gt 2.0 x 10e6 CD34 cells/kg consistently
  promote engraftment in HLA-matched setting
• Doses gt 8.0 x 10e6 CD34 cells/kg may be
  deleterious
• What about T-cell, B-cell, DC, (stromal cell,
  endothelial cell) and regulatory cell content?

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Effect of AMD3100 on PBPC Mobilization

• Results in rapid (1 hr) mobilization of PBPC in
  several murine strains
• Broxmeyer et al, Blood, 2001811a
• Dan Link, unpublished data
• Safely induces CD34 cell mobilization in healthy
  volunteers within 6-9 hours in a dose dependent
  manner
• Liles et al, Blood, 2003
• Combination with G-CSF in healthy volunteers
  results in synergistic effects on CD34 cell
  mobilization
• Liles et al, Blood, 2002109a

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Function of HPC and T-cells Mobilized by AMD3100

• Initial studies suggest higher content of SCID
  repopulating cells compared to G-CSF
• Srour et al, ASH 2003
• Similar engraftment capacity when competed
  against G-CSF mobilized murine HPC
• Dan Link, ASH 2003 and unpublished
• No obvious differences in alloreactivity of
  murine T-cells mobilized by AMD3100 vs G-CSF
• Dipersio, ASH 2003 and unpublished

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AMD3100 Based Stem Cell Mobilization in
HLA-Identical Donors

• Study Rationale
• G-CSF based stem cell mobilization is morbid,
  expensive, and time consuming
• Adversely effects donor quality of life
• Rates of GVHD still significant
• Possibly higher rates of late complications
• There is room for improvement

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Hypotheses

• Treatment of healthy HLA-matched sibling donors
  with AMD3100 will result in the rapid
  mobilization of CD34 cells and lymphocytes
• Compared to G-CSF, treatment of donors with
  AMD3100 will cause less morbidity and more rapid
  CD34 cell mobilization
• The allografts collected following AMD3100 will
  be functionally competent and promote engraftment
  with kinetics similar to G-CSF
• The risk of acute GVHD using allografts mobilized
  following AMD3100 should be similar that using
  G-CSF based on preliminary murine experiments
  (Rettig et al, presented at ASH 2003)

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Eligibility

• Patients with advanced hematological malignancy
• Ages 18-65
• HLA-identical Sibling donor available
• Adequate organ function

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AMD3100 Based Stem Cell Mobilization in
HLA-Identical Donors

• Aim 1
• Determine proportion of donors who mobilize
  allograft containing gt 2.0 CD34 cells/kg within
  2 collections (clinical trial)
• Aim 2
• Determine proportion of patients with neutrophil
  engraftment by day21 after transplantation
  (clinical trial)
• Determine the rates of GVHD and immune
  reconstitution

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CD34 Cell Mobilization by AMD3100 in Normal
Volunteers
Liles et al, Blood , 2003
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AMD3100 Mobilization
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G-CSF Mobilization
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
G-CSF 10?g/kg
G-CSF 10?g/kg
G-CSF 10?g/kg
G-CSF 10?g/kg
G-CSF 10?g/kg
G-CSF 10?g/kg
Leukapheresis (if needed)
Commence leukapheresis (20 liters)

• If AMD3100 mobilization yielded graft with
  gt2.0x10e6/kg,then G-CSF mobilized graft
  cryopreserved as back-up if engraftment does
  not occur. Backup graft must contain at least
  2.0x10e6 CD34 cells/kg
• If not, G-CSF mobilized graft used for
  transplantation

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Study Methods

•  Leukapheresis Procedure
• 20 Liters of blood processed on Cobe Spectra LP
  performed
• daily until target CD34 cell dose of 2.0 x
  10e6/kg reached.
•  Conditioning Regimen
• Cyclophosphamide 60mg/kg iv on days 3 and 2
• Single dose TBI (550cGy) on day 1
• PBSC allograft transplanted on day 0
•  GVHD Prophylaxis
• Cyclosporine at 3mg/kg actual body weight
  beginning
• Day 1. Target level 200-400ng/ml. No MTX
  given.
• Growth Factor Post Transplant
• G-CSF at 5mcg/kg s.c. beginning day 1,
  continuing
• until ANCgt 1500/ul for 3 consecutive days

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Patient/Donor Characteristics
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CD34 Cell Mobilization Following AMD3100
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Fold increase in CD34 cell count after AMD3100
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Allograft Analysis
 
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Comparison of Allograft Composition
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Transplant Results
 
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Correlative Work

• Study functional properties of Stem Cells
  mobilized by AMD3100 with G-CSF
• Phenotypic differences (CD34CD38-, AC133, ALDH)
• Cell cycle status
• Engraftment capacity in immunodeficient mice
• In vitro migration
• In vitro transducibility using retroviral and
  lentiviral vectors
• Gene expression profiling (expression of
  proapoptotic genes)
• Assess other progenitor cell populations (MSC,
  EPC)
• Phenotypic/functional analysis of T- and
  dendritic cells

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Conclusions

• Administration of AMD3100 to Healthy HLA-matched
  donors results in a modest but sufficient
  increase in CD34 cell count within 4 hours of
  injection
• Three of four donors collected an allograft
  containing gt2.0x10e6/kg recipient weight after
  one or two leukapheresis procedures
• AMD3100 administration is not associated with any
  significant acute toxicity in normal donors

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Conclusions

• Allografts collected following AMD3100 are
  functional, and engraft with kinetics similar to
  G-CSF mobilized allografts
• The optimal interval between AMD3100 injection
  and initiation of apheresis remains to be
  determined
• The minimum number of CD34 cells collected
  following AMD3100 necessary to promote
  engraftment is unclear, but grafts containing
  between 2.0-3.0x10e6 Cd34 cells/kg appear
  sufficient
• Accrual to this trial is ongoing