AMD 3100 (Mozobil Plerixafor) to Mobilize Stem Cells for Donation

Peripheral blood progenitor cells (PBPC) have become the preferred source of hematopoietic
stem cells for allogeneic transplantation because of technical ease of collection and shorter
time required for engraftment. Traditionally, granulocyte-colony stimulating factor (G-CSF)
has been used to procure the peripheral blood stem cell graft. Although regimens using G-CSF
usually succeed in collecting adequate numbers of PBPC from healthy donors, 5%-10% will
mobilize stem cells poorly and may require multiple large volume apheresis or bone marrow
harvesting. Although G-CSF is generally well tolerated in healthy donors, it may be
associated with bone pain, headache, myalgia and rarely life threatening side effects like
stroke, myocardial infarction and splenic rupture.

AMD3100 is a bicyclam compound that inhibits the binding of stromal cell derived factor-1
(SDF-1) to its cognate receptor CXCR4. CXCR4 is present on CD34+ hematopoietic progenitor
cells and its interaction with SDF-1 plays a pivotal role in the homing of CD34+ cells in the
bone marrow. Inhibition of the CXCR4-SDF1 axis by AMD3100 releases CD34+ cells into the
circulation, which can then be collected easily by apheresis. Recently, a published report
demonstrated that large numbers of CD34+ cells were rapidly mobilized in healthy volunteers
following a single subcutaneous injection of AMD3100. Remarkably, the number of CD34+ cells
collected by apheresis following a single injection of AMD3100 was comparable to the number
of CD34+ cells collected from historical controls receiving 5 days of G-CSF prior to stem
cell mobilization. Although the study population is relatively small, side-effects to this
agent have been mild and transient with no serious complications having been reported. The
ability to collect a large quantity of PBPC with a single injection of this drug makes this
an attractive agent for mobilizing donors of allogeneic PBPC. However, the immunologic
profiles of AMD3100 mobilized cells, in terms of lymphocyte content (T cell, B cell, NK cell,
immuno-regulatory T cell), T cell polarization status (TH1 versus TH2), status of antigen
presenting cells (DC1 versus DC2), alloreactive potential, and preservation of reactivity to
infectious agents [e.g. Epstein Barr Virus (EBV), Cytomegalovirus (CMV)] are unknown.
Consequently, whether AMD3100 mobilized PBPC would be suitable for use as an allograft is
uncertain. In this study we will collect PBPCs following a single subcutaneous injection of
AMD3100 from healthy donors who have previously had PBPC collected using standard G-CSF
mobilization. The AMD3100 mobilized cells, G-CSF mobilized cells, and circulating cells prior
to both AMD3100 and G-CSF mobilization will be analyzed in terms of cellular content and
function of lymphocytes, NK cells, and antigen presenting cells. AMD3100 mobilized PBPC will
be collected for the purpose of research studies and will not be used for therapeutic
purposes.

The primary objective is to characterize the immunological properties of AMD3100 mobilized
(cytokine gene expression profiles) T-cells compared to G-CSF mobilized T-cells.

Secondary endpoints include the cellular content and other immune properties of AMD3100
mobilized cells yields of hematopoietic progenitor cells, immune cells, and other cellular
subsets collected by apheresis in subjects undergoing G-CSF and AMD3100 mobilization and the
safety profile of AMD3100.

- INCLUSION CRITERIA:

1. Mobilization and collection of PBPC using G-CSF at least 60 days prior to
protocol enrollment (stem cell donors enrolled on Branch transplant protocols or
healthy volunteers enrolled on 96-H-0049: Use of granulocyte colony stimulating
factor mobilized leukapheresis collections from healthy volunteers).

2. Ages greater than or equal to 18 years and less than or equal to 80 years.

3. Normal renal function: creatinine less than 1.5 mg/dl.

4. Normal liver function: total bilirubin less than 1.5mg/dl, alanine
aminotransferase (ALT) 6 -41 U/L, aspartate aminotransferase (AST) 9-34 U/L.

5. Normal blood count: white blood cell (WBC) 3000-10000/mm(3)

granulocytes greater than 1500/mm(3)

platelets greater than 150,000/mm(3)

hemoglobin (females greater than 11.1 g/dl, males greater than 12.7 g/dl).

6. Subject must be eligible for normal blood donation and fit to undergo apheresis
procedure (antecubital veins must be adequate for peripheral access during
apheresis).

7. Ability to comprehend the investigational nature of the study and provide
informed consent.

EXCLUSION CRITERIA: Any of the Following

1. Active infection or history of recurrent infection- hepatitis B and C (HBsAg,
Anti-HBc, Anti-HCV), HIV and human T- lymphocytic virus (HTLV-1).

2. History of autoimmune disease such as rheumatoid arthritis, systemic lupus
erythematous.

3. History of cancer within the past 5 years excluding basal cell or squamous cell
carcinoma of the skin.

4. History of any hematologic disorders including thromboembolic disease.

5. History of cardiac disease such as uncontrolled hypertension, peripheral vascular
disease, myocardial infarction, cardiac arrhythmias OR related symptoms such as
tachycardia, chest pain, shortness of breath which have required medical intervention
OR treatment or a Framingham coronary disease risk prediction score of greater than
10% 10 year coronary heart disease (CHD) risk.

6. History of cerebrovascular disease, transient ischemic attack, or stroke.

7. Pregnant or lactating.

8. Severe psychiatric illness: mental deficiency sufficiently severe as to make informed
consent impossible