Allograft for Sickle Cell Disease and Thalassemia

A human lymphocyte antigen (HLA)-matched sibling donor will receive filgrastim (G-CSF) 10
to16 µg/kg/d subcutaneously or intravenously for up to 6 days with apheresis collections of
PBPC on day 5 (and day 6 if required). The product will be collected by leukophoresis with a
goal of ≥ 10 x 106 CD34+ cells/kg, with a minimum of 5 x 106 CD34+ cells/kg.

The patient will receive a preparative regimen of Alemtuzumab to be infused on days -7 to -3,
followed by 300 cGy TBI given as a single dose on day -2. Sirolimus at a dose of 5mg/day to
maintain trough levels between 10-15ng/ml will be started on day -1. The PBPC graft targeted
to deliver 10 x 106 CD34+ cells/kg (at minimum, 5 x 106 CD34+ cells/kg) will be infused on
day 0 On days +14, +30, +60 and +100 the chimeric status of patients will be assessed by
microsatellite analysis of the peripheral blood. More frequent monitoring may be required.

Sickle cell patients with pulmonary hypertension will meet with a Pulmonary Medicine Consult
to determine appropriate management prior to SCT.

Patients with fever or suspected minor infection should await resolution of symptoms before
starting the conditioning regimen.

Iron chelation must be discontinued > 48 hours before initiating the conditioning regimen.

Hydroxyurea must be discontinued one day prior to initiating the conditioning regimen.

Inclusion Criteria:

- Inclusion criteria - Recipient

Disease specific:

Sickle Cell Disease - Patients with sickle cell disease at high risk for disease related
morbidity or mortality, defined by having irreversible end-organ damage (A, B, C,D, or E)
or potentially reversible complication(s) not ameliorated by hydroxyurea (F):

A. Stroke defined as a clinically significant neurologic event that is accompanied by an
infarct on cerebral MRI OR an abnormal trans-cranial Doppler examination (≥200m/s); OR

B. Sickle cell related renal insufficiency defined by a creatinine level ≥1.5 times the
upper limit of normal and kidney biopsy consistent with sickle cell nephropathy OR
nephrotic syndrome OR creatinine clearance < 50mL/min OR requiring peritoneal or
hemodialysis. OR

C. Pulmonary hypertension as defined by tricuspid regurgitant jet velocity (TRV) of ≥
2.5m/s at least 3 weeks after a vaso-occlusive crisis; OR

D. Recurrent tricorporal priapism defined as at least two episodes of an erection lasting
≥4 hours involving the corpora cavernosa and corpus spongiosa; OR

E. Sickle hepatopathy defined as EITHER ferritin >1000mcg/L OR direct bilirubin >0.4 mg/dL
at baseline; OR

F. Any one of the below complications

1. Vaso-occlusive crises

2. Acute chest syndrome

3. Osteonecrosis of 2 or more joints

4. Red cell alloimmunization

Thalassemia - Patients with thalassemia who have grade 2 or 3 iron overload,
determined by the presence of 2 or more of the following:

• portal fibrosis by liver biopsy inadequate chelation history (defined as failure to
maintain adequate compliance with chelation with desferroxamine initiated within 18
months of the first transfusion and administered subcutaneously for 8-10 hours at
least 5 days each week) hepatomegaly of greater than 2 cm below the costochondral
margin

Non-disease specific:

Ages ≥ 18 but ≤ 45

6/6 HLA matched family donor available

Ability to comprehend and willing to sign an informed consent, assent obtained from
minors

Negative serum pregnancy test

Inclusion criteria - Donor

6/6 HLA identical family donor

Weight > 20 kg (in so far that the weight difference between recipient and donor does
not exceed a reasonable likelihood of being able to obtain an adequate cell dose from
the donor within two aphereses)

Fit to receive G-CSF and give peripheral blood stem cells (normal blood counts,
normotensive, and no history of stroke)

Ability to comprehend and willing to sign an informed consent

Exclusion Criteria:

Exclusion criteria - Recipient

Any of the following would exclude the subject from participating

ECOG performance status of 3 or more or Lanksy performance status of <40

Diffusion capacity of carbon monoxide (DLCO) <50% predicted (corrected for hemoglobin
and alveolar volume)

Baseline oxygen saturation of <85% or PaO2 <70

Left ventricular ejection fraction: <40% estimated by ECHO

Transaminases > 5x upper limit of normal for age

Evidence of uncontrolled bacterial, viral, or fungal infections (currently taking
medication and progression of clinical symptoms) within one month prior to starting
the conditioning regimen

Major anticipated illness or organ failure incompatible with survival from PBSC
transplant

Pregnant or lactating

Women of child-bearing potential and men must agree to use adequate contraception
(hormonal or barrier method of birth control; abstinence) prior to study entry, for
the duration of study participation, and for 90 days following completion of therapy.
Should a woman become pregnant or suspect she is pregnant while participating in this
study, she should inform her treating physician immediately.

A female of child-bearing potential is any woman (regardless of sexual orientation,
having undergone a tubal ligation, or remaining celibate by choice) who meets the
following criteria:

- Has not undergone a hysterectomy or bilateral oophorectomy; or

- Has not been naturally postmenopausal for at least 12 consecutive months (i.e.,
has had menses at any time in the preceding 12 consecutive months)

Major ABO mismatch

Exclusion criteria - Donor

Any of the following would exclude the donor from participating

Pregnant or lactating

Women of child-bearing potential and men must agree to use adequate contraception
(hormonal or barrier method of birth control; abstinence) prior to study entry, for
the duration of study participation, and for 90 days following completion of therapy.
Should a woman become pregnant or suspect she is pregnant while participating in this
study, she should inform her treating physician immediately.

A female of child-bearing potential is any woman (regardless of sexual orientation,
having undergone a tubal ligation, or remaining celibate by choice) who meets the
following criteria:

- Has not undergone a hysterectomy or bilateral oophorectomy; or

- Has not been naturally postmenopausal for at least 12 consecutive months (i.e.,
has had menses at any time in the preceding 12 consecutive months)

HIV positive

Hemoglobin S > 50%, or beta thalassemia intermediate