Unrelated HSCT in Patients With Fanconi Anemia

The major obstacle to successful alternate donor HCT for patients with Fanconi Anemia is
graft failure. While T-cell depletion decreases the incidence of aGVHD, its effect on
improving long term survival is unproven. To potentially improve engraftment rate, we have
chosen a relatively new immunosuppressive agent, fludarabine (FLU), FLU is an antineoplastic
agent that has been shown to be an effective immunosuppressive agen in BMT conditioning
therapy. The addition of FLU to the commonly used preparative regimen of CY and TBU in
Fanconi Anemia patients may improve engraftment rates.

Based on all presented data and its outcome, hematopoietic stem cell transplantation with
the use of total body irradiation (450 cGy), cyclophosphamide (10 mg/kg IV) and fludarabine
(35 mg/m2 IV) as preparative cytoreductive therapy has become the standard treatment for the
hematologic manifestations of Fanconi Anemia at CHLA. However, the use of Isolex 300i will
be replaced by CliniMACS in processing T-cell depletion.

The CliniMACS CD34 Reagent System is an investigational medical device that has not yet been
approved by the FDA. This device is used in vitro to select and enrich specific cell
populations. When using the CliniMACS CD34 Reagent, the system selects CD34+ cells from
heterogenous hematological cell populations for transplantation in cases where this is
clinically indicated. Based on the gathered data, CliniMACS has not been a contributing
factor in the toxicity of patients, although may have a potential of eliciting "antibody"
reactions in some patients, the process has been of significant life-saving benefit as
compared to the potential risks.

Inclusion Criteria:

- Patients must be > 2 months and < 21 years of age with a diagnosis of Fanconi anemia.

- Patients must have an HLA-A, B, DRB1 identical or 1 antigen mismatched related
(non-sibling) or unrelated donor. Patients and donors will be typed for HLA-A and B
using serological or molecular techniques and for DRB1 using high resolution
molecular typing. (Patients with a 2 antigen mismatched related donor will be
eligible for the protocol but evaluated separately).

- Patients with FA must have high risk genotype or aplastic anemia (AA) or
myelodysplastic syndrome without excess blasts.

- Aplastic anemia is defined as having at least one of the following:

1. platelet count <20 x 109/L

2. ANC <5 x 108/L

3. Hgb <8 g/dL with at least one of the following:

1. transfusion dependence

2. supportive care toxicity

- Myelodysplastic syndrome with multilineage dysplasia with or without chromosomal
anomalies.

- High risk genotype (e.g. IVS-4 or exon 14 FANCC mutations)

- Adequate major organ function including:

- Cardiac: ejection fraction >45%

- Renal: creatinine clearance >40 mL/min.

- Hepatic: no clinical evidence of hepatic failure (e.g. coagulopathy, ascites)

- Karnofsky performance status >70% or Lansky >50%

- Women of child bearing age must be using adequate birth control and have a negative
pregnancy test.

Exclusion Criteria:

- Available HLA-genotypically identical related donor.

- The harvested marrow (prior to TCD) should contain a minimum of 2.5 x 108 nucleated
cells/kg recipient body weight with a goal of >5.0 x 108 nucleated cells/kg recipient
body weight.

- Positive lymphocytotoxic crossmatch against donor (T cells and B cells)

- History of gram negative sepsis or systemic fungal infection (proven or suspected
based on radiographic studies).

- Myelodysplastic syndrome with excess blasts or leukemia.

- Active CNS leukemia at time of HCT.

- Malignant solid tumor (e.g. squamous cell carcinoma of the head/neck/cervix) within 2
years of HCT.

- Pregnant or lactating female.

- Prior radiation therapy preventing use of TBI 450 cGy.