Thrombocytopenia and Bleeding in Wiskott-Aldrich Syndrome (WAS) Patients

Wiskott Aldrich Syndrome is an X-linked disease characterized by immunodeficiency, eczema and
thrombocytopenia; a milder form of the disease known as X-Linked thrombocytopenia also
exists. The thrombocytopenia in both WAS and XLT is characterized by: severe thrombocytopenia
with platelet counts frequently less than 10-30,000/ul; small platelets which may be
dysfunctional; and, as a result, a high rate of serious bleeding including intracranial
hemorrhage.

Because eltrombopag has been shown to be remarkably efficacious in substantially increasing
platelet counts in a high percentage of ITP patients, this study seeks to effectively treat
patients who exhibit similar pathologies, as well as evaluate the state of platelets in
patients with WAS and relate it to clinical bleeding. It also aims to demonstrate whether
eltrombopag administered daily will enhance stem cell function, increase platelet production
and platelet count, and reduce bleeding in patients with WAS.

Inclusion Criteria:

In order to be eligible for study entry, subjects must comply with the following:

- Males from 3 months old to 80 years old

- Signed written informed consent obtained prior to study entry

- Clinical diagnosis of WAS or XLT

- Platelet levels less than 100 x 109/L

- Adequate renal and hepatic function (creatinine and bilirubin less than or equal to
1.5 x IULN, AST and ALT less than or equal to 2.5 x IULN)

Exclusion Criteria:

Any patient is ineligible for study entry if he/she:

- Over the age of 80

- Women (only males are eligible)

- fertile men who are not practicing or who are unwilling to practice birth control
while enrolled in the study or until at least 6 months after treatment

- Aspirin, aspirin-containing compounds, salicylates, non-steroidal anti-inflammatory
medications (NSAIDS), clopidogrel or ticlopidine, warfarin or other vitamin K
antagonists, unfractionated or low molecular heparin within 7 days of first infusion

- Red blood cell transfusion in the past four weeks

- Elevated (> 1.5 x ULN) prothrombin time (PT) or partial thromboplastin time (PTT)

- New York Heart Classification III or IV heart disease. Other severe cardiovascular or
cardiopulmonary disease, including COPD.

- Known HIV infection, hepatitis B or C infection

- Any infection requiring antibiotic treatment within 3 days

- Other concurrent medical or psychiatric conditions that, in the Investigator's
opinion, may be likely to confound study interpretation or prevent completion of study
procedures and follow-up examinations.

- Prior malignancy with less than a 5-year disease-free interval, excluding nonmelanoma
skin cancers and carcinoma in situ of the cervix